diff --git a/csaf_2_1/informativeTests.js b/csaf_2_1/informativeTests.js
index 0ecb389f..e15078a9 100644
--- a/csaf_2_1/informativeTests.js
+++ b/csaf_2_1/informativeTests.js
@@ -1,6 +1,5 @@
 export {
   informativeTest_6_3_3,
-  informativeTest_6_3_5,
   informativeTest_6_3_6,
   informativeTest_6_3_7,
   informativeTest_6_3_8,
@@ -11,5 +10,6 @@ export {
 export { informativeTest_6_3_1 } from './informativeTests/informativeTest_6_3_1.js'
 export { informativeTest_6_3_2 } from './informativeTests/informativeTest_6_3_2.js'
 export { informativeTest_6_3_4 } from './informativeTests/informativeTest_6_3_4.js'
+export { informativeTest_6_3_5 } from './informativeTests/informativeTest_6_3_5.js'
 export { informativeTest_6_3_12 } from './informativeTests/informativeTest_6_3_12.js'
 export { informativeTest_6_3_18 } from './informativeTests/informativeTest_6_3_18.js'
diff --git a/csaf_2_1/informativeTests/informativeTest_6_3_5.js b/csaf_2_1/informativeTests/informativeTest_6_3_5.js
new file mode 100644
index 00000000..c9683eb6
--- /dev/null
+++ b/csaf_2_1/informativeTests/informativeTest_6_3_5.js
@@ -0,0 +1,24 @@
+import { walkHashes } from '../shared/csafHelpers/walkHashes.js'
+
+/**
+ * @param {unknown} doc
+ * @returns
+ */
+export function informativeTest_6_3_5(doc) {
+  const ctx = {
+    infos: /** @type {Array<{ message: string; instancePath: string }>} */ ([]),
+  }
+
+  walkHashes(doc, ({ path, hash }) => {
+    hash.file_hashes.forEach((fileHash, fileHashIndex) => {
+      if (typeof fileHash.value === 'string' && fileHash.value.length < 64) {
+        ctx.infos.push({
+          instancePath: `${path}/${fileHashIndex}/value`,
+          message: 'use of short hash',
+        })
+      }
+    })
+  })
+
+  return ctx
+}
diff --git a/csaf_2_1/shared/csafHelpers/walkHashes.js b/csaf_2_1/shared/csafHelpers/walkHashes.js
index 8591290b..994a9b44 100644
--- a/csaf_2_1/shared/csafHelpers/walkHashes.js
+++ b/csaf_2_1/shared/csafHelpers/walkHashes.js
@@ -4,9 +4,15 @@ const ajv = new Ajv()
 
 const hashSchema = /** @type {const} */ ({
   additionalProperties: true,
-  optionalProperties: {
+  properties: {
     file_hashes: {
-      elements: { additionalProperties: true, properties: {} },
+      elements: {
+        additionalProperties: true,
+        properties: {
+          algorithm: { type: 'string' },
+          value: { type: 'string' },
+        },
+      },
     },
   },
 })
@@ -67,10 +73,15 @@ const validateInput = ajv.compile(inputSchema)
 const validateFullProductName = ajv.compile(fullProductNameSchema)
 const validateBranch = ajv.compile(branchSchema)
 const validateProductPath = ajv.compile(productPathSchema)
+const validateFileHash = ajv.compile(hashSchema)
+
+/**
+ * @typedef {{ file_hashes: Array<{ algorithm: string; value: string }> }} FileHashEntry
+ */
 
 /**
  * @param {any} doc
- * @param {(params: { path: string; hash: {} }) => void} onHashFound
+ * @param {(params: { path: string; hash: FileHashEntry }) => void} onHashFound
  */
 export function walkHashes(doc, onHashFound) {
   if (!validateInput(doc)) {
@@ -85,6 +96,7 @@ export function walkHashes(doc, onHashFound) {
 
       fullProductName.product_identification_helper?.hashes?.forEach(
         (hash, hashIndex) => {
+          if (!validateFileHash(hash)) return
           onHashFound({
             path: `/product_tree/full_product_names/${fullProductNameIndex}/product_identification_helper/hashes/${hashIndex}/file_hashes`,
             hash,
@@ -106,6 +118,7 @@ export function walkHashes(doc, onHashFound) {
 
       branch.product?.product_identification_helper?.hashes?.forEach(
         (hash, hashIndex) => {
+          if (!validateFileHash(hash)) return
           onHashFound({
             path: `${prefix}${branchIndex}/product/product_identification_helper/hashes/${hashIndex}/file_hashes`,
             hash,
@@ -128,6 +141,7 @@ export function walkHashes(doc, onHashFound) {
 
     productPath.full_product_name?.product_identification_helper?.hashes?.forEach(
       (hash, hashIndex) => {
+        if (!validateFileHash(hash)) return
         onHashFound({
           path: `/product_tree/product_paths/${productPathIndex}/full_product_name/product_identification_helper/hashes/${hashIndex}/file_hashes`,
           hash,
diff --git a/tests/csaf_2_1/informativeTest_6_3_5.js b/tests/csaf_2_1/informativeTest_6_3_5.js
new file mode 100644
index 00000000..7c54377f
--- /dev/null
+++ b/tests/csaf_2_1/informativeTest_6_3_5.js
@@ -0,0 +1,97 @@
+import assert from 'node:assert'
+import { informativeTest_6_3_5 } from '../../csaf_2_1/informativeTests.js'
+
+describe('informativeTest_6_3_5', function () {
+  it('only runs on relevant documents', function () {
+    assert.equal(informativeTest_6_3_5({ document: 'mydoc' }).infos.length, 0)
+  })
+
+  it('skip invalid hash value', function () {
+    const result = informativeTest_6_3_5({
+      product_tree: {
+        full_product_names: [
+          {
+            name: 'Product A',
+            product_id: 'CSAFPID-9080700',
+            product_identification_helper: {
+              hashes: [
+                {
+                  filename: 'product_a.so',
+                },
+              ],
+            },
+          },
+        ],
+      },
+    })
+    assert.equal(result.infos.length, 0)
+  })
+
+  it('detects short hash in product_paths', function () {
+    const result = informativeTest_6_3_5({
+      product_tree: {
+        product_paths: [
+          {
+            full_product_name: {
+              name: 'Product A',
+              product_id: 'CSAFPID-0001',
+              product_identification_helper: {
+                hashes: [
+                  {
+                    file_hashes: [
+                      {
+                        algorithm: 'md5',
+                        value: 'd41d8cd98f00b204e9800998ecf8427e',
+                      },
+                    ],
+                    filename: 'product_b.so',
+                  },
+                ],
+              },
+            },
+          },
+        ],
+      },
+    })
+    assert.equal(result.infos.length, 1)
+    assert.equal(
+      result.infos[0].instancePath,
+      '/product_tree/product_paths/0/full_product_name/product_identification_helper/hashes/0/file_hashes/0/value'
+    )
+  })
+
+  it('detects short hash in branches', function () {
+    const result = informativeTest_6_3_5({
+      product_tree: {
+        branches: [
+          {
+            category: 'vendor',
+            name: 'Vendor A',
+            product: {
+              name: 'Product A',
+              product_id: 'CSAFPID-0001',
+              product_identification_helper: {
+                hashes: [
+                  {
+                    file_hashes: [
+                      {
+                        algorithm: 'md5',
+                        value: 'd41d8cd98f00b204e9800998ecf8427e',
+                      },
+                    ],
+                    filename: 'product_c.so',
+                  },
+                ],
+              },
+            },
+          },
+        ],
+      },
+    })
+    assert.equal(result.infos.length, 1)
+    assert.equal(
+      result.infos[0].instancePath,
+      '/product_tree/branches/0/product/product_identification_helper/hashes/0/file_hashes/0/value'
+    )
+  })
+})