diff --git a/src/bio.c b/src/bio.c
index 9d94144f57..51e18973fc 100644
--- a/src/bio.c
+++ b/src/bio.c
@@ -2456,6 +2456,7 @@ int wolfSSL_BIO_flush(WOLFSSL_BIO* bio)
         bio = wolfSSL_BIO_new(wolfSSL_BIO_s_socket());
         if (bio) {
             const char* port;
+            int portVal = 0;
 #ifdef WOLFSSL_IPV6
             const char* ipv6Start = XSTRSTR(str, "[");
             const char* ipv6End = XSTRSTR(str, "]");
@@ -2466,8 +2467,13 @@ int wolfSSL_BIO_flush(WOLFSSL_BIO* bio)
 #endif
                 port = XSTRSTR(str, ":");
 
-            if (port != NULL)
-                bio->port = (word16)XATOI(port + 1);
+            if (port != NULL) {
+                portVal = XATOI(port + 1);
+                /* Reject out-of-range ports instead of truncating to word16. */
+                if ((portVal < 0) || (portVal > 65535))
+                    portVal = 0;
+                bio->port = (word16)portVal;
+            }
             else
                 port = str + XSTRLEN(str); /* point to null terminator */
 
diff --git a/src/internal.c b/src/internal.c
index fc8bc191f1..7114801c04 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -12867,6 +12867,8 @@ static int BuildMD5(WOLFSSL* ssl, Hashes* hashes, const byte* sender)
         }
     }
 
+    ForceZero(md5_result, WC_MD5_DIGEST_SIZE);
+
     WC_FREE_VAR_EX(md5, ssl->heap, DYNAMIC_TYPE_HASHCTX);
 
     return ret;
@@ -12912,6 +12914,8 @@ static int BuildSHA(WOLFSSL* ssl, Hashes* hashes, const byte* sender)
         }
     }
 
+    ForceZero(sha_result, WC_SHA_DIGEST_SIZE);
+
     WC_FREE_VAR_EX(sha, ssl->heap, DYNAMIC_TYPE_HASHCTX);
 
     return ret;
@@ -15355,7 +15359,7 @@ int SetupStoreCtxCallback(WOLFSSL_X509_STORE_CTX** store_pt,
         if (args->certIdx == 0) {
             FreeX509(&ssl->peerCert);
             InitX509(&ssl->peerCert, 0, ssl->heap);
-            if (CopyDecodedToX509(&ssl->peerCert, args->dCert) == 0)
+            if (CopyDecodedToX509(&ssl->peerCert, args->dCert) != 0)
                 WOLFSSL_MSG("Unable to copy to ssl->peerCert");
             store->current_cert = &ssl->peerCert; /* use existing X509 */
         }
@@ -23775,6 +23779,14 @@ static int CheckResumptionConsistency(WOLFSSL* ssl)
 static int DoChangeCipherSpecTls13(WOLFSSL* ssl)
 {
     word32 i = ssl->buffers.inputBuffer.idx;
+#ifdef WOLFSSL_DTLS13
+    if (ssl->options.dtls) {
+        /* CCS is not part of DTLS 1.3; discard the record without alerting so a
+         * spoofed CCS cannot tear down the handshake. */
+        ssl->buffers.inputBuffer.idx += ssl->curSize;
+        return 0;
+    }
+#endif
     if (ssl->options.handShakeState == HANDSHAKE_DONE) {
         SendAlert(ssl, alert_fatal, unexpected_message);
         WOLFSSL_ERROR_VERBOSE(UNKNOWN_RECORD_TYPE);
@@ -25226,6 +25238,8 @@ static int BuildMD5_CertVerify(const WOLFSSL* ssl, byte* digest)
         }
     }
 
+    ForceZero(md5_result, WC_MD5_DIGEST_SIZE);
+
     WC_FREE_VAR_EX(md5, ssl->heap, DYNAMIC_TYPE_HASHCTX);
 
     return ret;
@@ -25272,6 +25286,8 @@ static int BuildSHA_CertVerify(const WOLFSSL* ssl, byte* digest)
         }
     }
 
+    ForceZero(sha_result, WC_SHA_DIGEST_SIZE);
+
     WC_FREE_VAR_EX(sha, ssl->heap, DYNAMIC_TYPE_HASHCTX);
 
     return ret;
@@ -42548,8 +42564,18 @@ static int DefTicketEncCb(WOLFSSL* ssl, byte key_name[WOLFSSL_TICKET_NAME_SZ],
         /* Update AAD with index. */
         aad[WOLFSSL_TICKET_NAME_SZ - 1] |= keyIdx;
 
+#ifndef SINGLE_THREADED
+        /* Hold the lock over the key/expiry read so a concurrent regen can't swap the key mid-decrypt. */
+        if (wc_LockMutex(&keyCtx->mutex) != 0) {
+            WOLFSSL_MSG("Couldn't lock key context mutex");
+            return WOLFSSL_TICKET_RET_REJECT;
+        }
+#endif
         /* Check expirary */
         if (keyCtx->expirary[keyIdx] <= LowResTimer()) {
+#ifndef SINGLE_THREADED
+            wc_UnLockMutex(&keyCtx->mutex);
+#endif
             return WOLFSSL_TICKET_RET_REJECT;
         }
 
@@ -42557,6 +42583,9 @@ static int DefTicketEncCb(WOLFSSL* ssl, byte key_name[WOLFSSL_TICKET_NAME_SZ],
         ret = TicketEncDec(keyCtx->key[keyIdx], WOLFSSL_TICKET_KEY_SZ, iv, aad,
                            aadSz, ticket, inLen, ticket, outLen, mac, ssl->heap,
                            0);
+#ifndef SINGLE_THREADED
+        wc_UnLockMutex(&keyCtx->mutex);
+#endif
         if (ret != 0) {
             return WOLFSSL_TICKET_RET_REJECT;
         }
diff --git a/src/ocsp.c b/src/ocsp.c
index 4048e7628e..85be2e16e4 100644
--- a/src/ocsp.c
+++ b/src/ocsp.c
@@ -1159,7 +1159,7 @@ OcspResponse* wolfSSL_d2i_OCSP_RESPONSE_bio(WOLFSSL_BIO* bio,
             return NULL;
         dataAlloced = 1;
 
-        len = wolfSSL_BIO_read(bio, (char *)data, (int)flen);
+        len = wolfSSL_BIO_read(bio, (char *)data, (int)fcur);
     }
 #endif
     else
diff --git a/src/quic.c b/src/quic.c
index caf8ab9e71..4ff27285ed 100644
--- a/src/quic.c
+++ b/src/quic.c
@@ -1239,6 +1239,11 @@ int wolfSSL_quic_hkdf_expand(uint8_t* dest, size_t destlen,
 
     WOLFSSL_ENTER("wolfSSL_quic_hkdf_expand");
 
+    if (secretlen > INT_MAX || infolen > INT_MAX) {
+        ret = WOLFSSL_FAILURE;
+        goto cleanup;
+    }
+
     pctx = wolfSSL_EVP_PKEY_CTX_new_id(WC_NID_hkdf, NULL);
     if (pctx == NULL) {
         ret = WOLFSSL_FAILURE;
@@ -1279,6 +1284,11 @@ int wolfSSL_quic_hkdf(uint8_t* dest, size_t destlen,
 
     WOLFSSL_ENTER("wolfSSL_quic_hkdf");
 
+    if (secretlen > INT_MAX || saltlen > INT_MAX || infolen > INT_MAX) {
+        ret = WOLFSSL_FAILURE;
+        goto cleanup;
+    }
+
     pctx = wolfSSL_EVP_PKEY_CTX_new_id(WC_NID_hkdf, NULL);
     if (pctx == NULL) {
         ret = WOLFSSL_FAILURE;
@@ -1348,6 +1358,10 @@ int wolfSSL_quic_aead_encrypt(uint8_t* dest, WOLFSSL_EVP_CIPHER_CTX* ctx,
      * TODO: there is some fiddling in OpenSSL+quic in regard to CCM ciphers
      *       which we need to check.
      */
+    if (plainlen > INT_MAX || aadlen > INT_MAX) {
+        return WOLFSSL_FAILURE;
+    }
+
     if (wolfSSL_EVP_CipherInit(ctx, NULL, NULL, iv, 1) != WOLFSSL_SUCCESS
         || wolfSSL_EVP_CipherUpdate(
                 ctx, NULL, &len, aad, (int)aadlen) != WOLFSSL_SUCCESS
@@ -1373,7 +1387,7 @@ int wolfSSL_quic_aead_decrypt(uint8_t* dest, WOLFSSL_EVP_CIPHER_CTX* ctx,
     const uint8_t* tag;
 
     /* See rationale for wolfSSL_quic_aead_encrypt() on why this is here */
-    if (enclen > INT_MAX || ctx->authTagSz > (int)enclen) {
+    if (enclen > INT_MAX || aadlen > INT_MAX || ctx->authTagSz > (int)enclen) {
         return WOLFSSL_FAILURE;
     }
 
diff --git a/src/sniffer.c b/src/sniffer.c
index 7f0c432255..380121c8db 100644
--- a/src/sniffer.c
+++ b/src/sniffer.c
@@ -4482,6 +4482,10 @@ static int ProcessCertificate(const byte* input, int* sslBytes,
     }
 #endif
 
+    if (OPAQUE24_LEN > *sslBytes) {
+        SetError(BAD_CERT_MSG_STR, error, session, FATAL_ERROR_STATE);
+        return WOLFSSL_FATAL_ERROR;
+    }
     ato24(input, &certChainSz);
     *sslBytes -= CERT_HEADER_SZ;
     input += CERT_HEADER_SZ;
@@ -4491,6 +4495,10 @@ static int ProcessCertificate(const byte* input, int* sslBytes,
         return WOLFSSL_FATAL_ERROR;
     }
 
+    if (OPAQUE24_LEN > *sslBytes) {
+        SetError(BAD_CERT_MSG_STR, error, session, FATAL_ERROR_STATE);
+        return WOLFSSL_FATAL_ERROR;
+    }
     ato24(input, &certSz);
     input += OPAQUE24_LEN;
     if (*sslBytes < (int)certSz) {
diff --git a/src/ssl.c b/src/ssl.c
index f5a309552c..04afe47409 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -12361,7 +12361,13 @@ void* wolfSSL_GetHKDFExtractCtx(WOLFSSL* ssl)
     {
     #if defined(OPENSSL_EXTRA) || defined(OPENSSL_EXTRA_X509_SMALL)
         WOLFSSL_ENTER("wolfSSL_set_verify_depth");
-        ssl->options.verifyDepth = (byte)depth;
+        /* Reject out-of-range depths; valid range is 0 to MAX_CHAIN_DEPTH. */
+        if ((ssl == NULL) || (depth < 0) || (depth > MAX_CHAIN_DEPTH)) {
+            WOLFSSL_MSG("Bad depth argument, too large or less than 0");
+        }
+        else {
+            ssl->options.verifyDepth = (byte)depth;
+        }
     #endif
     }
 
@@ -16065,6 +16071,7 @@ int wolfSSL_RAND_pseudo_bytes(unsigned char* buf, int num)
     (void)hash;
     (void)secret;
 #endif
+    ForceZero(secret, DRBG_SEED_LEN);
     return ret;
 }
 
@@ -16939,20 +16946,39 @@ int wolfSSL_FIPS_drbg_uninstantiate(WOLFSSL_DRBG_CTX *ctx)
 void wolfSSL_FIPS_drbg_free(WOLFSSL_DRBG_CTX *ctx)
 {
     if (ctx != NULL) {
+        int locked = 0;
         /* As safety check if free'ing the default drbg, then mark global NULL.
          * Technically the user should not call free on the default drbg. */
+    #ifndef WOLFSSL_MUTEX_INITIALIZER
+        /* wolfSSL_Cleanup may free the mutex before this runs. */
+        if ((globalRNGMutex_valid == 1) && (wc_LockMutex(&globalRNGMutex) == 0))
+    #else
+        if (wc_LockMutex(&globalRNGMutex) == 0)
+    #endif
+            locked = 1;
         if (ctx == gDrbgDefCtx) {
             gDrbgDefCtx = NULL;
         }
+        if (locked)
+            wc_UnLockMutex(&globalRNGMutex);
         wolfSSL_FIPS_drbg_uninstantiate(ctx);
         XFREE(ctx, NULL, DYNAMIC_TYPE_OPENSSL);
     }
 }
 WOLFSSL_DRBG_CTX* wolfSSL_FIPS_get_default_drbg(void)
 {
+    int locked = 0;
+#ifndef WOLFSSL_MUTEX_INITIALIZER
+    if ((globalRNGMutex_valid == 1) && (wc_LockMutex(&globalRNGMutex) == 0))
+#else
+    if (wc_LockMutex(&globalRNGMutex) == 0)
+#endif
+        locked = 1;
     if (gDrbgDefCtx == NULL) {
         gDrbgDefCtx = wolfSSL_FIPS_drbg_new(0, 0);
     }
+    if (locked)
+        wc_UnLockMutex(&globalRNGMutex);
     return gDrbgDefCtx;
 }
 void wolfSSL_FIPS_get_timevec(unsigned char* buf, unsigned long* pctr)
diff --git a/src/ssl_api_crl_ocsp.c b/src/ssl_api_crl_ocsp.c
index 677aad4681..1cb77a3c66 100644
--- a/src/ssl_api_crl_ocsp.c
+++ b/src/ssl_api_crl_ocsp.c
@@ -395,6 +395,9 @@ int wolfSSL_get_ocsp_producedDate(
     size_t producedDate_space,
     int *producedDateFormat)
 {
+    if (ssl == NULL)
+        return BAD_FUNC_ARG;
+
     if ((ssl->ocspProducedDateFormat != ASN_UTC_TIME) &&
         (ssl->ocspProducedDateFormat != ASN_GENERALIZED_TIME))
         return BAD_FUNC_ARG;
@@ -415,6 +418,9 @@ int wolfSSL_get_ocsp_producedDate(
 int wolfSSL_get_ocsp_producedDate_tm(WOLFSSL *ssl, struct tm *produced_tm) {
     int idx = 0;
 
+    if (ssl == NULL)
+        return BAD_FUNC_ARG;
+
     if ((ssl->ocspProducedDateFormat != ASN_UTC_TIME) &&
         (ssl->ocspProducedDateFormat != ASN_GENERALIZED_TIME))
         return BAD_FUNC_ARG;
diff --git a/src/ssl_api_pk.c b/src/ssl_api_pk.c
index d18590e8ac..59adff1482 100644
--- a/src/ssl_api_pk.c
+++ b/src/ssl_api_pk.c
@@ -393,7 +393,7 @@ int wolfSSL_CTX_check_private_key(const WOLFSSL_CTX* ctx)
             res = check_cert_key(ctx->certificate, privateKey, altPrivateKey,
                 ctx->heap, ctx->privateKeyDevId, ctx->privateKeyLabel,
                 ctx->privateKeyId, ctx->altPrivateKeyDevId,
-                ctx->altPrivateKeyLabel, ctx->altPrivateKeyId) != 0;
+                ctx->altPrivateKeyLabel, ctx->altPrivateKeyId) == 1;
         }
     #ifdef WOLFSSL_BLIND_PRIVATE_KEY
         /* Dispose of the unblinded buffers. */
diff --git a/src/ssl_bn.c b/src/ssl_bn.c
index 74d828da93..a88ee73a6c 100644
--- a/src/ssl_bn.c
+++ b/src/ssl_bn.c
@@ -326,23 +326,21 @@ const WOLFSSL_BIGNUM* wolfSSL_BN_value_one(void)
             wolfSSL_BN_free(one);
             one = NULL;
         }
-        else
+        else {
     #ifndef SINGLE_THREADED
-        /* Ensure global has not been set by another thread. */
-        if (bn_one == NULL)
-    #endif
-        {
+            void* expected = NULL;
+            /* Publish atomically so a losing thread frees only its own object,
+             * never a pointer already handed to another thread. */
+            if (!wolfSSL_Atomic_Ptr_CompareExchange((void* volatile*)&bn_one,
+                    &expected, one)) {
+                wolfSSL_BN_free(one);
+                one = (WOLFSSL_BIGNUM*)expected;
+            }
+    #else
             /* Set this big number as the global. */
             bn_one = one;
-        }
-    #ifndef SINGLE_THREADED
-        /* Check if another thread has set the global. */
-        if (bn_one != one) {
-            /* Dispose of this big number and return the global.  */
-            wolfSSL_BN_free(one);
-            one = bn_one;
-        }
     #endif
+        }
     }
 
     return one;
diff --git a/src/ssl_crypto.c b/src/ssl_crypto.c
index 92ae36e582..294afb1096 100644
--- a/src/ssl_crypto.c
+++ b/src/ssl_crypto.c
@@ -2880,6 +2880,8 @@ void wolfSSL_DES_ede3_cbc_encrypt(const unsigned char* input,
             }
         }
         wc_Des3Free(des3);
+
+        ForceZero(key, DES3_KEY_SIZE);
     }
 
     WC_FREE_VAR_EX(des3, NULL, DYNAMIC_TYPE_CIPHER);
diff --git a/src/ssl_misc.c b/src/ssl_misc.c
index 072f2cc133..fc7e1a4a9b 100644
--- a/src/ssl_misc.c
+++ b/src/ssl_misc.c
@@ -70,6 +70,11 @@ static int wolfssl_read_bio_file(WOLFSSL_BIO* bio, char** data)
 
             /* Update total read. */
             ret += sz;
+            /* Cap total like the direct-file path to avoid int overflow. */
+            if (ret > MAX_WOLFSSL_FILE_SIZE) {
+                sz = BUFFER_E;
+                break;
+            }
             /* Calculate remaining unused memory. */
             remaining = READ_BIO_FILE_CHUNK - (ret % READ_BIO_FILE_CHUNK);
             /* Check for space remaining. */
diff --git a/src/ssl_p7p12.c b/src/ssl_p7p12.c
index 27cf6c8963..23aa47d297 100644
--- a/src/ssl_p7p12.c
+++ b/src/ssl_p7p12.c
@@ -903,6 +903,7 @@ int wolfSSL_PKCS7_encode_certs(PKCS7* pkcs7, WOLFSSL_STACK* certs,
 {
     int ret;
     WOLFSSL_PKCS7* p7;
+    WOLFSSL_STACK* certHead = certs;
     WOLFSSL_ENTER("wolfSSL_PKCS7_encode_certs");
 
     if (!pkcs7 || !certs || !out) {
@@ -912,10 +913,6 @@ int wolfSSL_PKCS7_encode_certs(PKCS7* pkcs7, WOLFSSL_STACK* certs,
 
     p7 = (WOLFSSL_PKCS7*)pkcs7;
 
-    /* take ownership of certs */
-    p7->certs = certs;
-    /* TODO: takes ownership even on failure below but not on above failure. */
-
     if (pkcs7->certList) {
         WOLFSSL_MSG("wolfSSL_PKCS7_encode_certs called multiple times on same "
                     "struct");
@@ -957,6 +954,9 @@ int wolfSSL_PKCS7_encode_certs(PKCS7* pkcs7, WOLFSSL_STACK* certs,
         certs = certs->next;
     }
 
+    /* certs are now incorporated into pkcs7; take ownership (earlier failures leave ownership with the caller). */
+    p7->certs = certHead;
+
     if (wc_PKCS7_SetSignerIdentifierType(pkcs7, DEGENERATE_SID) != 0) {
         WOLFSSL_MSG("wc_PKCS7_SetSignerIdentifierType error");
         return WOLFSSL_FAILURE;
diff --git a/src/tls.c b/src/tls.c
index 59a9b2f373..9ebdfaf082 100644
--- a/src/tls.c
+++ b/src/tls.c
@@ -10089,6 +10089,11 @@ static int TLSX_KeyShare_ProcessPqcClient_ex(WOLFSSL* ssl,
             WOLFSSL_MSG("GenPqcKey memory error");
             ret = MEMORY_E;
         }
+        else {
+            /* Zero so an unconditional wc_MlKemKey_Free is safe even if Init is
+             * skipped on an id2type failure. */
+            XMEMSET(kem, 0, sizeof(MlKemKey));
+        }
         if (ret == 0) {
             ret = mlkem_id2type(keyShareEntry->group, &type);
         }
@@ -12152,6 +12157,10 @@ static void TLSX_PreSharedKey_FreeAll(PreSharedKey* list, void* heap)
 
     while ((current = list) != NULL) {
         list = current->next;
+        /* identity may hold an in-place decrypted ticket whose bytes are the
+         * resumption master secret; wipe before returning it to the heap. */
+        if (current->identity != NULL)
+            ForceZero(current->identity, current->identityLen);
         XFREE(current->identity, heap, DYNAMIC_TYPE_TLSX);
         XFREE(current, heap, DYNAMIC_TYPE_TLSX);
     }
@@ -13485,6 +13494,14 @@ static int TLSX_ClientCertificateType_Parse(WOLFSSL* ssl, const byte* input,
     else if (msgType == server_hello || msgType == encrypted_extensions) {
         /* parse it in client side */
         if (length == 1) {
+            /* Reject a server-selected type the client did not offer. */
+            if (!IsCertTypeListed(*input,
+                    ssl->options.rpkState.sending_ClientCertTypeCnt,
+                    ssl->options.rpkState.sending_ClientCertTypes)) {
+                SendAlert(ssl, alert_fatal, illegal_parameter);
+                WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
+                return INVALID_PARAMETER;
+            }
             ssl->options.rpkState.received_ClientCertTypeCnt  = 1;
             ssl->options.rpkState.received_ClientCertTypes[0] = *input;
         }
@@ -13685,6 +13702,15 @@ static int TLSX_ServerCertificateType_Parse(WOLFSSL* ssl, const byte* input,
         if (length != 1)                     /* length slould be 1 */
             return BUFFER_E;
 
+        /* Reject a server-selected type the client did not offer. */
+        if (!IsCertTypeListed(*input,
+                ssl->options.rpkState.sending_ServerCertTypeCnt,
+                ssl->options.rpkState.sending_ServerCertTypes)) {
+            SendAlert(ssl, alert_fatal, illegal_parameter);
+            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
+            return INVALID_PARAMETER;
+        }
+
         ssl->options.rpkState.received_ServerCertTypeCnt  = 1;
         ssl->options.rpkState.received_ServerCertTypes[0] = *input;
     }
@@ -14589,6 +14615,17 @@ static int TLSX_ECH_ExpandOuterExtensions(WOLFSSL* ssl, WOLFSSL_ECH* ech,
     return ret;
 }
 
+/* Header bytes reserved before the ECH inner ClientHello (DTLS uses a larger handshake header than TLS). */
+static word32 TLSX_EchInnerHeaderSz(const WOLFSSL* ssl)
+{
+#ifdef WOLFSSL_DTLS13
+    return ssl->options.dtls ? DTLS13_HANDSHAKE_HEADER_SZ : HANDSHAKE_HEADER_SZ;
+#else
+    (void)ssl;
+    return HANDSHAKE_HEADER_SZ;
+#endif
+}
+
 /* return status after attempting to open the hpke encrypted ech extension, if
  * successful the inner client hello will be stored in
  * ech->innerClientHelloLen */
@@ -14676,7 +14713,7 @@ static int TLSX_ExtractEch(WOLFSSL* ssl, WOLFSSL_ECH* ech,
     if (ret == 0) {
         ret = wc_HpkeContextOpenBase(ech->hpke, ech->hpkeContext, aad, aadLen,
             ech->outerClientPayload, ech->innerClientHelloLen,
-            ech->innerClientHello + HANDSHAKE_HEADER_SZ);
+            ech->innerClientHello + TLSX_EchInnerHeaderSz(ssl));
     }
 
 #ifdef HAVE_SECRET_CALLBACK
@@ -14894,7 +14931,7 @@ static int TLSX_ECH_Parse(WOLFSSL* ssl, const byte* readBuf, word16 size,
             XFREE(ech->innerClientHello, ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
         /* allocate the inner payload buffer */
         ech->innerClientHello =
-            (byte*)XMALLOC(ech->innerClientHelloLen + HANDSHAKE_HEADER_SZ,
+            (byte*)XMALLOC(ech->innerClientHelloLen + TLSX_EchInnerHeaderSz(ssl),
             ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
         if (ech->innerClientHello == NULL) {
             XFREE(aadCopy, ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
diff --git a/src/x509_str.c b/src/x509_str.c
index 710d18b74c..3ee233165d 100644
--- a/src/x509_str.c
+++ b/src/x509_str.c
@@ -446,9 +446,15 @@ static int X509StoreVerifyCert(WOLFSSL_X509_STORE_CTX* ctx)
     #endif
         SetupStoreCtxError(ctx, ret);
     #if defined(OPENSSL_ALL) || defined(WOLFSSL_QT)
-        if (ctx->store->verify_cb)
-            ret = ctx->store->verify_cb(ret >= 0 ? 1 : 0, ctx) == 1 ?
-                                                        WOLFSSL_SUCCESS : ret;
+        if (ctx->store->verify_cb) {
+            if (ctx->store->verify_cb(ret >= 0 ? 1 : 0, ctx) == 1) {
+                ret = WOLFSSL_SUCCESS;
+            }
+            else {
+                /* Callback rejection is terminal; don't let a later pass override it. */
+                return -1;
+            }
+        }
     #endif
     }
 #if !defined(NO_ASN_TIME) && defined(OPENSSL_ALL)
@@ -2374,6 +2380,8 @@ WOLFSSL_STACK* wolfSSL_X509_STORE_GetCerts(WOLFSSL_X509_STORE_CTX* s)
             }
         }
         else {
+            wolfSSL_X509_free(x509);
+            x509 = NULL;
             goto error;
         }
         found = 1;
diff --git a/tests/api/test_certman.c b/tests/api/test_certman.c
index 25c203a4b2..f8c13f4a2d 100644
--- a/tests/api/test_certman.c
+++ b/tests/api/test_certman.c
@@ -2866,6 +2866,99 @@ int test_wolfSSL_CRL_critical_idp(void)
     return EXPECT_RESULT();
 }
 
+int test_wolfSSL_cert_critical_policy_constraints(void)
+{
+    EXPECT_DECLS;
+#if !defined(NO_CERTS) && !defined(NO_RSA) && !defined(WOLFSSL_NO_ASN_STRICT)
+    /* Critical policyConstraints is parsed but never enforced, so RFC 5280 Sec 4.2 requires rejecting the cert rather than silently accepting it. */
+    static const unsigned char cert_crit_policy[] = {
+        0x30, 0x82, 0x03, 0x38, 0x30, 0x82, 0x02, 0x20, 0xa0, 0x03, 0x02,
+        0x01, 0x02, 0x02, 0x14, 0x39, 0xd1, 0x63, 0xf8, 0xb6, 0x8f, 0x51,
+        0xc0, 0x2c, 0xef, 0x38, 0x87, 0x6d, 0x40, 0x1c, 0x2c, 0xc0, 0xcd,
+        0xa1, 0x9a, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7,
+        0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, 0x30, 0x23, 0x31, 0x21, 0x30,
+        0x1f, 0x06, 0x03, 0x55, 0x04, 0x03, 0x0c, 0x18, 0x50, 0x6f, 0x6c,
+        0x69, 0x63, 0x79, 0x43, 0x6f, 0x6e, 0x73, 0x74, 0x72, 0x61, 0x69,
+        0x6e, 0x74, 0x43, 0x72, 0x69, 0x74, 0x54, 0x65, 0x73, 0x74, 0x30,
+        0x1e, 0x17, 0x0d, 0x32, 0x30, 0x30, 0x31, 0x30, 0x31, 0x30, 0x30,
+        0x30, 0x30, 0x30, 0x30, 0x5a, 0x17, 0x0d, 0x34, 0x30, 0x30, 0x31,
+        0x30, 0x31, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x5a, 0x30, 0x23,
+        0x31, 0x21, 0x30, 0x1f, 0x06, 0x03, 0x55, 0x04, 0x03, 0x0c, 0x18,
+        0x50, 0x6f, 0x6c, 0x69, 0x63, 0x79, 0x43, 0x6f, 0x6e, 0x73, 0x74,
+        0x72, 0x61, 0x69, 0x6e, 0x74, 0x43, 0x72, 0x69, 0x74, 0x54, 0x65,
+        0x73, 0x74, 0x30, 0x82, 0x01, 0x22, 0x30, 0x0d, 0x06, 0x09, 0x2a,
+        0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03,
+        0x82, 0x01, 0x0f, 0x00, 0x30, 0x82, 0x01, 0x0a, 0x02, 0x82, 0x01,
+        0x01, 0x00, 0xa5, 0x09, 0xd5, 0xa6, 0xb1, 0x07, 0xb6, 0x7e, 0xa0,
+        0x51, 0x74, 0x5d, 0x1b, 0x3f, 0x92, 0x3d, 0xb2, 0xf4, 0x2d, 0xfc,
+        0xd9, 0xa1, 0xa7, 0xc4, 0x2d, 0x28, 0x3e, 0xa5, 0x2e, 0xc0, 0xba,
+        0xcc, 0x82, 0x3f, 0xf7, 0x80, 0x86, 0x4f, 0xb5, 0x3b, 0xeb, 0x67,
+        0x3f, 0x57, 0x43, 0x72, 0xd0, 0x1e, 0xdb, 0xd9, 0x4f, 0xb5, 0x14,
+        0x12, 0xec, 0xa4, 0x7a, 0x2a, 0xb8, 0xd7, 0x12, 0x64, 0x30, 0x32,
+        0xe9, 0xfc, 0x3a, 0x91, 0xe3, 0xa6, 0x59, 0x08, 0x11, 0xde, 0xd0,
+        0xb0, 0xfa, 0xcf, 0x31, 0x37, 0x3d, 0xa8, 0xd6, 0xa1, 0xb0, 0x84,
+        0x25, 0x2d, 0x05, 0x8a, 0x33, 0x32, 0x24, 0x94, 0xa5, 0xef, 0x65,
+        0xb6, 0x58, 0xfa, 0x94, 0xbd, 0x3a, 0xef, 0xfd, 0xcd, 0xeb, 0x56,
+        0xc4, 0x87, 0x65, 0x45, 0x5f, 0xe1, 0x14, 0xa9, 0x3c, 0x6e, 0x94,
+        0xa1, 0xc4, 0xfc, 0x67, 0xcd, 0xff, 0xb4, 0xdb, 0xbd, 0x0e, 0x56,
+        0x26, 0x94, 0xa8, 0xdc, 0xc2, 0x9d, 0xef, 0xb3, 0x95, 0x27, 0xc4,
+        0x97, 0x00, 0xae, 0x9a, 0x42, 0x48, 0x51, 0xe2, 0xbd, 0xb6, 0x12,
+        0xf4, 0xe0, 0xaf, 0x21, 0xd2, 0x92, 0xc3, 0xc1, 0x7d, 0xb1, 0xad,
+        0x11, 0xc9, 0x4e, 0xed, 0xb6, 0x80, 0x81, 0x2a, 0x86, 0xb2, 0xf2,
+        0x6e, 0x8c, 0x6d, 0xe0, 0x55, 0x7a, 0x00, 0x76, 0x81, 0x73, 0x27,
+        0x26, 0x3a, 0xd7, 0xe9, 0x86, 0xfb, 0x26, 0x14, 0x10, 0x1f, 0x0f,
+        0xf8, 0xfd, 0x41, 0x67, 0x37, 0xdc, 0x51, 0xcf, 0xd7, 0x44, 0x2f,
+        0x77, 0x85, 0xb2, 0xbb, 0xd4, 0xe9, 0xf4, 0xbb, 0xfc, 0xb0, 0x08,
+        0xaf, 0xba, 0x8a, 0x73, 0x4c, 0x62, 0x97, 0x7b, 0xd2, 0x5d, 0x01,
+        0x32, 0x5c, 0x84, 0x2d, 0xc7, 0x06, 0x53, 0x13, 0x25, 0xa7, 0xf2,
+        0x85, 0xce, 0x18, 0x7c, 0x80, 0x7d, 0x46, 0xcf, 0x59, 0x4a, 0x6a,
+        0x79, 0xad, 0xfd, 0x10, 0xf3, 0x02, 0x03, 0x01, 0x00, 0x01, 0xa3,
+        0x64, 0x30, 0x62, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x1d, 0x0e, 0x04,
+        0x16, 0x04, 0x14, 0x57, 0x3b, 0x53, 0xa1, 0xea, 0xb0, 0x48, 0x46,
+        0x26, 0x1c, 0x05, 0xa4, 0xb4, 0xca, 0x4c, 0xe7, 0x2d, 0x6c, 0x69,
+        0xc2, 0x30, 0x1f, 0x06, 0x03, 0x55, 0x1d, 0x23, 0x04, 0x18, 0x30,
+        0x16, 0x80, 0x14, 0x57, 0x3b, 0x53, 0xa1, 0xea, 0xb0, 0x48, 0x46,
+        0x26, 0x1c, 0x05, 0xa4, 0xb4, 0xca, 0x4c, 0xe7, 0x2d, 0x6c, 0x69,
+        0xc2, 0x30, 0x0f, 0x06, 0x03, 0x55, 0x1d, 0x24, 0x01, 0x01, 0xff,
+        0x04, 0x05, 0x30, 0x03, 0x80, 0x01, 0x00, 0x30, 0x0f, 0x06, 0x03,
+        0x55, 0x1d, 0x13, 0x01, 0x01, 0xff, 0x04, 0x05, 0x30, 0x03, 0x01,
+        0x01, 0xff, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7,
+        0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, 0x03, 0x82, 0x01, 0x01, 0x00,
+        0x25, 0xb6, 0xa5, 0xb5, 0xbd, 0xa3, 0x8e, 0xcf, 0x06, 0x09, 0x67,
+        0x28, 0x03, 0xf4, 0x6e, 0x6d, 0xa9, 0x4a, 0xe4, 0xac, 0x2e, 0xda,
+        0xdb, 0x98, 0x38, 0x50, 0x5b, 0xdf, 0xc6, 0x17, 0xc7, 0x1c, 0xea,
+        0x05, 0xd8, 0xea, 0xf4, 0x84, 0x41, 0x21, 0xc1, 0x3c, 0x59, 0x4e,
+        0xa3, 0x6e, 0x82, 0xa8, 0xda, 0x28, 0x81, 0x29, 0x02, 0x74, 0x75,
+        0x56, 0xf2, 0xd3, 0x70, 0x3f, 0x24, 0x21, 0x08, 0x73, 0xe9, 0xb2,
+        0x15, 0xc8, 0x30, 0x8c, 0x3b, 0xbe, 0x2a, 0x1c, 0x64, 0xfc, 0xb8,
+        0x9d, 0x9d, 0xa4, 0xf7, 0xda, 0x05, 0x93, 0x6c, 0x1c, 0xaf, 0xa8,
+        0xd3, 0xef, 0x0f, 0x9a, 0x52, 0x84, 0xce, 0x03, 0xbb, 0x06, 0x64,
+        0x8e, 0xa2, 0x70, 0x5e, 0x03, 0xb8, 0xa0, 0xe4, 0x58, 0x84, 0x1b,
+        0xf9, 0xa9, 0xfd, 0x9c, 0xc8, 0xf1, 0x8c, 0x98, 0x0d, 0x22, 0x3d,
+        0x54, 0x80, 0xb2, 0x12, 0xf9, 0xba, 0xa7, 0xfa, 0xcc, 0x77, 0x48,
+        0xe3, 0xe9, 0x46, 0x54, 0x49, 0xd4, 0x9c, 0x60, 0x53, 0x02, 0x4c,
+        0x6b, 0x0a, 0x73, 0xe5, 0x16, 0x0f, 0xea, 0xa2, 0xed, 0xbb, 0xab,
+        0xce, 0xbe, 0x29, 0x45, 0xff, 0xc1, 0xcf, 0x4e, 0x4a, 0x25, 0x8b,
+        0xc8, 0x32, 0x50, 0x62, 0x6a, 0x4a, 0x4c, 0x1a, 0xbc, 0xc4, 0xf4,
+        0x66, 0xf2, 0x19, 0x57, 0x4f, 0x5c, 0x7a, 0xab, 0xe0, 0x79, 0x19,
+        0xeb, 0x9d, 0xc3, 0x56, 0xfa, 0x99, 0xf5, 0xb0, 0x5c, 0xe3, 0x92,
+        0xa4, 0x8a, 0x7c, 0x42, 0xcf, 0xd8, 0x25, 0x80, 0x47, 0x8d, 0x83,
+        0x3e, 0xd7, 0xef, 0x60, 0x1c, 0xfd, 0xe0, 0xd1, 0x2d, 0x04, 0xbf,
+        0xe7, 0x3d, 0x1d, 0xb2, 0xda, 0xfd, 0x4c, 0x7f, 0x20, 0x73, 0xa7,
+        0x7a, 0xd1, 0xf2, 0x43, 0x64, 0x22, 0x9d, 0x7e, 0x2b, 0x7a, 0xeb,
+        0xe6, 0xcd, 0xea, 0x57, 0xea, 0xe1, 0x86, 0x78, 0xcf, 0x09, 0x4d,
+        0x90, 0xb9, 0x62
+    };
+    WOLFSSL_CERT_MANAGER* cm = NULL;
+
+    ExpectNotNull(cm = wolfSSL_CertManagerNew());
+    ExpectIntNE(wolfSSL_CertManagerLoadCABuffer(cm, cert_crit_policy,
+        sizeof(cert_crit_policy), WOLFSSL_FILETYPE_ASN1), WOLFSSL_SUCCESS);
+    wolfSSL_CertManagerFree(cm);
+#endif
+    return EXPECT_RESULT();
+}
+
 int test_wolfSSL_CRL_unknown_critical_ext(void)
 {
     EXPECT_DECLS;
diff --git a/tests/api/test_certman.h b/tests/api/test_certman.h
index 3511760145..868dca801d 100644
--- a/tests/api/test_certman.h
+++ b/tests/api/test_certman.h
@@ -48,6 +48,7 @@ int test_wolfSSL_CRL_duplicate_extensions(void);
 int test_wolfSSL_CRL_critical_idp(void);
 int test_wolfSSL_CRL_unknown_critical_ext(void);
 int test_wolfSSL_CRL_unknown_critical_entry_ext(void);
+int test_wolfSSL_cert_critical_policy_constraints(void);
 int test_wolfSSL_CertManagerCheckOCSPResponse(void);
 int test_various_pathlen_chains(void);
 int test_wolfSSL_CertManagerRejectMD5Cert(void);
@@ -82,6 +83,7 @@ int test_wolfSSL_CertManagerNameConstraint_skid_disambiguates(void);
     TEST_DECL_GROUP("certman", test_wolfSSL_CRL_critical_idp),             \
     TEST_DECL_GROUP("certman", test_wolfSSL_CRL_unknown_critical_ext),     \
     TEST_DECL_GROUP("certman", test_wolfSSL_CRL_unknown_critical_entry_ext), \
+    TEST_DECL_GROUP("certman", test_wolfSSL_cert_critical_policy_constraints), \
     TEST_DECL_GROUP("certman", test_wolfSSL_CertManagerCheckOCSPResponse),  \
     TEST_DECL_GROUP("certman", test_various_pathlen_chains),                \
     TEST_DECL_GROUP("certman", test_wolfSSL_CertManagerRejectMD5Cert),      \
diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c
index 12d4956caf..2251158543 100644
--- a/wolfcrypt/src/asn.c
+++ b/wolfcrypt/src/asn.c
@@ -21637,6 +21637,12 @@ WOLFSSL_TEST_VIS int DecodeExtensionType(const byte* input, word32 length,
         case INHIBIT_ANY_OID:
             VERIFY_AND_SET_OID(cert->inhibitAnyOidSet);
             WOLFSSL_MSG("Inhibit anyPolicy extension not supported yet.");
+        #ifndef WOLFSSL_NO_ASN_STRICT
+            if (critical) {
+                WOLFSSL_ERROR_VERBOSE(ASN_CRIT_EXT_E);
+                ret = ASN_CRIT_EXT_E;
+            }
+        #endif
             break;
 
    #ifndef IGNORE_NETSCAPE_CERT_TYPE
@@ -21661,6 +21667,12 @@ WOLFSSL_TEST_VIS int DecodeExtensionType(const byte* input, word32 length,
             cert->extPolicyConstCrit = critical ? 1 : 0;
             if (DecodePolicyConstraints(&input[idx], (int)length, cert) < 0)
                 return ASN_PARSE_E;
+        #ifndef WOLFSSL_NO_ASN_STRICT
+            if (critical) {
+                WOLFSSL_ERROR_VERBOSE(ASN_CRIT_EXT_E);
+                ret = ASN_CRIT_EXT_E;
+            }
+        #endif
             break;
     #ifdef WOLFSSL_SUBJ_DIR_ATTR
         case SUBJ_DIR_ATTR_OID:
@@ -32938,8 +32950,9 @@ int wc_BuildEccKeyDer(ecc_key* key, byte* output, word32 *outLen,
         ret = BAD_FUNC_ARG;
     }
 
-    /* Check key has parameters when encoding curve. */
-    if ((ret == 0) && curveIn && (key->dp == NULL)) {
+    /* Check key has parameters: key->dp->size is dereferenced below regardless
+     * of curveIn. */
+    if ((ret == 0) && (key->dp == NULL)) {
         ret = BAD_FUNC_ARG;
     }
     if (ret == 0)
diff --git a/wolfcrypt/src/pkcs7.c b/wolfcrypt/src/pkcs7.c
index 882a2af1ae..af15d1992a 100644
--- a/wolfcrypt/src/pkcs7.c
+++ b/wolfcrypt/src/pkcs7.c
@@ -6727,6 +6727,17 @@ static int wc_PKCS7_HandleOctetStrings(wc_PKCS7* pkcs7, byte* in, word32 inSz,
 
                     /* grow content buffer */
                     contBufSz = pkcs7->stream->accumContSz;
+                    /* Reject before the word32 add wraps and yields a tiny alloc for an oversized copy. */
+                    if (pkcs7->stream->expected >
+                            WOLFSSL_PKCS7_MAX_STREAM_ALLOC -
+                            pkcs7->stream->accumContSz) {
+                        WOLFSSL_MSG("PKCS7 accumulated content size too large");
+                        if (tempBuf != NULL) {
+                            XFREE(tempBuf, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+                        }
+                        ret = BUFFER_E;
+                        break;
+                    }
                     pkcs7->stream->accumContSz += pkcs7->stream->expected;
 
                     pkcs7->stream->content =