diff --git a/CHANGELOG.md b/CHANGELOG.md
index deb94b77..13b7b162 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,16 @@ Until `1.0.0`, minor releases may include breaking changes
   `$schema` out of both manifests. The plugin ships on merge to `main` and is
   versioned independently of this repository.
 
+### Security
+
+- **`@adrkit/core` and `@adrkit/mcp` now require `zod` `^4.6.6`**, up from
+  `^4.6.5`, so an install can no longer resolve a zod release affected by
+  [GHSA-mrhx-c7xc-m3w5](https://github.com/advisories/GHSA-mrhx-c7xc-m3w5)
+  (validating oversized constrained collections can exhaust memory). This
+  repository's lockfile already moved to 4.6.7 in #329; this raises the floor
+  that published installs see. The documentation site's lockfile moves to zod
+  4.6.7 as well.
+
 ## [0.20.0] - 2026-10-10
 
 This release adds a read-only REST server to the OCI image:
diff --git a/bun.lock b/bun.lock
index e801356b..36ffcea3 100644
--- a/bun.lock
+++ b/bun.lock
@@ -7,7 +7,7 @@
       "devDependencies": {
         "@types/bun": "latest",
         "typescript": "^6",
-        "zod": "^4.6.5",
+        "zod": "^4.6.6",
       },
     },
     "packages/adapters/agent-plugin": {
@@ -76,7 +76,7 @@
         "picomatch": "^4",
         "semver": "^7",
         "yaml": "^2.9.1",
-        "zod": "^4.6.5",
+        "zod": "^4.6.6",
       },
       "devDependencies": {
         "@types/bun": "latest",
@@ -104,7 +104,7 @@
       "dependencies": {
         "@adrkit/core": "workspace:*",
         "@modelcontextprotocol/server": "2.3.1",
-        "zod": "^4.6.5",
+        "zod": "^4.6.6",
       },
       "devDependencies": {
         "@modelcontextprotocol/client": "2.3.1",
diff --git a/package.json b/package.json
index ab99dc55..1368f6b9 100644
--- a/package.json
+++ b/package.json
@@ -54,6 +54,6 @@
   "devDependencies": {
     "@types/bun": "latest",
     "typescript": "^6",
-    "zod": "^4.6.5"
+    "zod": "^4.6.6"
   }
 }
diff --git a/packages/core/package.json b/packages/core/package.json
index f9b9f52e..6a822cd7 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -61,7 +61,7 @@
     "picomatch": "^4",
     "semver": "^7",
     "yaml": "^2.9.1",
-    "zod": "^4.6.5"
+    "zod": "^4.6.6"
   },
   "devDependencies": {
     "@types/bun": "latest",
diff --git a/packages/mcp/package.json b/packages/mcp/package.json
index 1a5cbb24..429e698c 100644
--- a/packages/mcp/package.json
+++ b/packages/mcp/package.json
@@ -47,7 +47,7 @@
   "dependencies": {
     "@adrkit/core": "workspace:*",
     "@modelcontextprotocol/server": "2.3.1",
-    "zod": "^4.6.5"
+    "zod": "^4.6.6"
   },
   "devDependencies": {
     "@modelcontextprotocol/client": "2.3.1",
diff --git a/site/bun.lock b/site/bun.lock
index 544ab5b5..d6e6f778 100644
--- a/site/bun.lock
+++ b/site/bun.lock
@@ -764,7 +764,7 @@
 
     "yocto-queue": ["yocto-queue@1.2.2", "", {}, "sha512-4LCcse/U2MHZ63HAJVE+v71o7yOdIe4cZ70Wpf8D/IyjDKYQLV5GD46B+hSTjJsvV5PztjvHoU580EftxjDZFQ=="],
 
-    "zod": ["zod@4.6.5", "", {}, "sha512-v5l/aFXZQeai4awLbOpSoHecE9UiMrnfx75tEXLjNonXVARxQ5mOeipTjROUchszUNCqnE+hqAMujRsRHsut2Q=="],
+    "zod": ["zod@4.6.7", "", {}, "sha512-g8W2D2kU6a8untc053fX1uVBKzM7yqAxW/3zwk83+6RyF2+SKOuV+c0wBDhUwzV1PaGapmZH+rmcUzPf+3CGwg=="],
 
     "zwitch": ["zwitch@2.0.4", "", {}, "sha512-bXE4cR/kVZhKZX/RjPEflHaKVhUVl85noU3v6b8apfQEc1x4A+zBxjZ4lN8LqGd6WZ3dl98pY4o717VFmoPp+A=="],