diff --git a/csaf_2_1/informativeTests.js b/csaf_2_1/informativeTests.js
index 7e914506..dbcb450a 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_6,
   informativeTest_6_3_7,
   informativeTest_6_3_8,
   informativeTest_6_3_9,
@@ -11,6 +10,7 @@ export { informativeTest_6_3_1 } from './informativeTests/informativeTest_6_3_1.
 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_6 } from './informativeTests/informativeTest_6_3_6.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'
 export { informativeTest_6_3_21_1 } from './informativeTests/informativeTest_6_3_21_1.js'
diff --git a/csaf_2_1/informativeTests/informativeTest_6_3_6.js b/csaf_2_1/informativeTests/informativeTest_6_3_6.js
new file mode 100644
index 00000000..70c06fd4
--- /dev/null
+++ b/csaf_2_1/informativeTests/informativeTest_6_3_6.js
@@ -0,0 +1,219 @@
+import { Ajv } from 'ajv/dist/jtd.js'
+import testURL from '#lib/informativeTests/shared/testURL.js'
+import { walkPath } from '#lib/walkPaths.js'
+
+const ajv = new Ajv()
+
+const referenceSchema = /** @type {const} */ ({
+  additionalProperties: true,
+  optionalProperties: {
+    url: { type: 'string' },
+    category: { type: 'string' },
+  },
+})
+
+const inputSchema = /** @type {const} */ ({
+  additionalProperties: true,
+  optionalProperties: {
+    document: {
+      additionalProperties: true,
+      optionalProperties: {
+        acknowledgments: {
+          elements: {
+            additionalProperties: true,
+            optionalProperties: {
+              urls: {
+                elements: { type: 'string' },
+              },
+            },
+          },
+        },
+        references: {
+          elements: referenceSchema,
+        },
+        aggregate_severity: {
+          additionalProperties: true,
+          optionalProperties: {
+            namespace: { type: 'string' },
+          },
+        },
+        distribution: {
+          additionalProperties: true,
+          optionalProperties: {
+            tlp: {
+              additionalProperties: true,
+              optionalProperties: {
+                url: { type: 'string' },
+              },
+            },
+          },
+        },
+        publisher: {
+          additionalProperties: true,
+          optionalProperties: {
+            namespace: { type: 'string' },
+          },
+        },
+      },
+    },
+    product_tree: {
+      additionalProperties: true,
+      optionalProperties: {
+        full_product_names: {
+          elements: {
+            additionalProperties: true,
+            optionalProperties: {
+              product_identification_helper: {
+                additionalProperties: true,
+                optionalProperties: {
+                  sbom_urls: { elements: { type: 'string' } },
+                  x_generic_uris: {
+                    elements: {
+                      additionalProperties: true,
+                      optionalProperties: {
+                        namespace: { type: 'string' },
+                        uri: { type: 'string' },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+        branches: {
+          elements: {
+            additionalProperties: true,
+            properties: {},
+          },
+        },
+        product_paths: {
+          elements: {
+            additionalProperties: true,
+            optionalProperties: {
+              full_product_name: {
+                additionalProperties: true,
+                optionalProperties: {
+                  product_identification_helper: {
+                    additionalProperties: true,
+                    optionalProperties: {
+                      sbom_urls: { elements: { type: 'string' } },
+                      x_generic_uris: {
+                        elements: {
+                          additionalProperties: true,
+                          optionalProperties: {
+                            namespace: { type: 'string' },
+                            uri: { type: 'string' },
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    },
+    vulnerabilities: {
+      elements: {
+        additionalProperties: true,
+        optionalProperties: {
+          remediations: {
+            elements: {
+              additionalProperties: true,
+              optionalProperties: {
+                url: { type: 'string' },
+              },
+            },
+          },
+          acknowledgments: {
+            elements: {
+              additionalProperties: true,
+              optionalProperties: {
+                urls: {
+                  elements: { type: 'string' },
+                },
+              },
+            },
+          },
+          references: {
+            elements: referenceSchema,
+          },
+        },
+      },
+    },
+  },
+})
+
+const validateInput = ajv.compile(inputSchema)
+const validateReference = ajv.compile(referenceSchema)
+
+/**
+ * CSAF 2.1 Informative Test 6.3.6:
+ * verifies that all non-self references using URL fields resolve to HTTP 2xx or 3xx.
+ *
+ * @param {unknown} doc
+ */
+export async function informativeTest_6_3_6(doc) {
+  const ctx = {
+    infos: /** @type {Array<{ message: string; instancePath: string }>} */ ([]),
+  }
+
+  if (!validateInput(doc)) {
+    return ctx
+  }
+
+  for (const path of [
+    '/document/acknowledgments[]/urls[]',
+    '/document/aggregate_severity/namespace',
+    '/document/distribution/tlp/url',
+    '/document/publisher/namespace',
+    '/product_tree/branches[*]/product/product_identification_helper/sbom_urls[]',
+    '/product_tree/branches[*]/product/product_identification_helper/x_generic_uris[]/namespace',
+    '/product_tree/branches[*]/product/product_identification_helper/x_generic_uris[]/uri',
+    '/product_tree/full_product_names[]/product_identification_helper/sbom_urls[]',
+    '/product_tree/full_product_names[]/product_identification_helper/x_generic_uris[]/namespace',
+    '/product_tree/full_product_names[]/product_identification_helper/x_generic_uris[]/uri',
+    '/product_tree/product_paths[]/full_product_name/product_identification_helper/sbom_urls[]',
+    '/product_tree/product_paths[]/full_product_name/product_identification_helper/x_generic_uris[]/namespace',
+    '/product_tree/product_paths[]/full_product_name/product_identification_helper/x_generic_uris[]/uri',
+    '/vulnerabilities[]/acknowledgments[]/urls[]',
+    '/vulnerabilities[]/remediations[]/url',
+  ]) {
+    await walkPath(doc, path, async (instancePath, value) => {
+      if (typeof value !== 'string') return
+      await testURL(value, () => {
+        ctx.infos.push({
+          instancePath,
+          message: 'use of non-self referencing urls failing to resolve',
+        })
+      })
+    })
+  }
+
+  for (const path of [
+    '/document/references[]',
+    '/vulnerabilities[]/references[]',
+  ]) {
+    await walkPath(doc, path, async (instancePath, value) => {
+      if (
+        !validateReference(value) ||
+        value.category === 'self' ||
+        typeof value.url !== 'string'
+      ) {
+        return
+      }
+
+      await testURL(value.url, () => {
+        ctx.infos.push({
+          instancePath: instancePath + '/url',
+          message: 'use of non-self referencing urls failing to resolve',
+        })
+      })
+    })
+  }
+
+  return ctx
+}
diff --git a/package.json b/package.json
index b5baaff3..c4a8f7a1 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,9 @@
   "repository": {
     "url": "https://github.com/secvisogram/csaf-validator-lib"
   },
+  "imports": {
+    "#*.js": "./*.js"
+  },
   "files": [
     "lib",
     "schemas",
diff --git a/tests/csaf_2_1/informativeTest_6_3_6.js b/tests/csaf_2_1/informativeTest_6_3_6.js
new file mode 100644
index 00000000..1c1a5e14
--- /dev/null
+++ b/tests/csaf_2_1/informativeTest_6_3_6.js
@@ -0,0 +1,8 @@
+import { informativeTest_6_3_6 } from '../../csaf_2_1/informativeTests.js'
+
+describe('informativeTest_6_3_6', function () {
+  it('returns no infos for invalid input', async function () {
+    const result = await informativeTest_6_3_6('not-an-object')
+    assert.equal(result.infos.length, 0)
+  })
+})