diff --git a/.appsec-tests/vpatch-CVE-2026-21643/CVE-2026-21643.yaml b/.appsec-tests/vpatch-CVE-2026-21643/CVE-2026-21643.yaml
new file mode 100644
index 00000000000..f1fde85d097
--- /dev/null
+++ b/.appsec-tests/vpatch-CVE-2026-21643/CVE-2026-21643.yaml
@@ -0,0 +1,19 @@
+## autogenerated on 2026-04-15 13:30:23
+id: CVE-2026-21643
+info:
+  name: CVE-2026-21643
+  author: crowdsec
+  severity: info
+  description: CVE-2026-21643 testing
+  tags: appsec-testing
+http:
+  - raw:
+      - |
+        GET /api/v1/init_consts HTTP/1.1
+        Host: {{Hostname}}
+        Site: tenant1; SELECT pg_sleep(8)--
+    cookie-reuse: true
+    matchers:
+    - type: status
+      status:
+       - 403
diff --git a/.appsec-tests/vpatch-CVE-2026-21643/config.yaml b/.appsec-tests/vpatch-CVE-2026-21643/config.yaml
new file mode 100644
index 00000000000..157a2509083
--- /dev/null
+++ b/.appsec-tests/vpatch-CVE-2026-21643/config.yaml
@@ -0,0 +1,5 @@
+## autogenerated on 2026-04-15 13:30:23
+appsec-rules:
+  - ./appsec-rules/crowdsecurity/base-config.yaml
+  - ./appsec-rules/crowdsecurity/vpatch-CVE-2026-21643.yaml
+nuclei_template: CVE-2026-21643.yaml
diff --git a/appsec-rules/crowdsecurity/vpatch-CVE-2026-21643.yaml b/appsec-rules/crowdsecurity/vpatch-CVE-2026-21643.yaml
new file mode 100644
index 00000000000..a7c4f33f283
--- /dev/null
+++ b/appsec-rules/crowdsecurity/vpatch-CVE-2026-21643.yaml
@@ -0,0 +1,33 @@
+## autogenerated on 2026-04-15 13:30:23
+name: crowdsecurity/vpatch-CVE-2026-21643
+description: 'Detects SQL injection in Fortinet FortiClientEMS via the Site HTTP header on /api/v1/init_consts.'
+rules:
+  - and:
+      - zones:
+          - URI
+        transform:
+          - lowercase
+        match:
+          type: contains
+          value: /api/v1/init_consts
+      - zones:
+          - HEADERS
+        variables:
+          - site
+        transform:
+          - lowercase
+        match:
+          type: contains
+          value: ';'
+
+labels:
+  type: exploit
+  service: http
+  confidence: 3
+  spoofable: 0
+  behavior: 'http:exploit'
+  label: 'FortiClientEMS - SQLI'
+  classification:
+    - cve.CVE-2026-21643
+    - attack.T1190
+    - cwe.CWE-89
diff --git a/collections/crowdsecurity/appsec-virtual-patching.yaml b/collections/crowdsecurity/appsec-virtual-patching.yaml
index e67dbb0c51b..f8591b12d9d 100644
--- a/collections/crowdsecurity/appsec-virtual-patching.yaml
+++ b/collections/crowdsecurity/appsec-virtual-patching.yaml
@@ -123,6 +123,7 @@ appsec-rules:
 - crowdsecurity/vpatch-CVE-2019-5418
 - crowdsecurity/vpatch-CVE-2025-52488
 - crowdsecurity/vpatch-CVE-2025-49132
+- crowdsecurity/vpatch-CVE-2026-21643
 - crowdsecurity/vpatch-CVE-2025-47812
 - crowdsecurity/vpatch-CVE-2024-51977
 - crowdsecurity/vpatch-CVE-2022-31499