diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 87bf07cc8..1612259c8 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -28,6 +28,14 @@ jobs:
         with:
           fetch-depth: 2
 
+      - name: Set up Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: "22.23.4"
+
+      - name: Verify Node.js security baseline
+        run: node scripts/check-node-version.cjs
+
       - name: Check if version changed
         id: version
         run: |
@@ -54,7 +62,10 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
-          node-version: "22"
+          node-version: "22.23.4"
+
+      - name: Verify Node.js security baseline
+        run: node scripts/check-node-version.cjs
 
       - name: Install dependencies
         run: npm ci
diff --git a/.github/workflows/performance.yml b/.github/workflows/performance.yml
index 1e1ad8a1e..11304eec6 100644
--- a/.github/workflows/performance.yml
+++ b/.github/workflows/performance.yml
@@ -36,10 +36,14 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
-          node-version: "22"
+          node-version: "22.23.4"
           cache: npm
           cache-dependency-path: pr/package-lock.json
 
+      - name: Verify Node.js security baseline
+        working-directory: pr
+        run: node scripts/check-node-version.cjs
+
       - name: Install and build candidate
         working-directory: pr
         run: |
diff --git a/.github/workflows/pr-validation.yml b/.github/workflows/pr-validation.yml
index 7f48864c3..583780bd5 100644
--- a/.github/workflows/pr-validation.yml
+++ b/.github/workflows/pr-validation.yml
@@ -19,7 +19,10 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
-          node-version: "22"
+          node-version: "22.23.4"
+
+      - name: Verify Node.js security baseline
+        run: node scripts/check-node-version.cjs
 
       - name: Install dependencies
         run: npm ci
@@ -42,7 +45,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: ["22", "24"]
+        node-version: ["22.23.4", "24.22.1"]
 
     steps:
       - name: Check out repository
@@ -53,6 +56,12 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
+      - name: Verify Node.js security baseline
+        run: node scripts/check-node-version.cjs
+
+      - name: Test Node.js security baseline guard
+        run: node --test test/integration/node-version.test.mjs
+
       - name: Install dependencies
         run: npm ci
 
@@ -79,9 +88,12 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
-          node-version: "22"
+          node-version: "22.23.4"
           cache: npm
 
+      - name: Verify Node.js security baseline
+        run: node scripts/check-node-version.cjs
+
       - name: Install dependencies
         run: npm ci
 
@@ -104,7 +116,9 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
-          node-version: "22"
+          node-version: "22.23.4"
+      - name: Verify Node.js security baseline
+        run: node scripts/check-node-version.cjs
       - name: Install dependencies
         run: npm ci
       - name: Build
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd58530b0..0170ffcae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## [Unreleased]
 
 ### Bugs Fixed
+- Require Node.js 22.23.4+, 24.22.1+, or 26.12.1+ on their respective release lines for security fixes.
 - **Breaking change on Unix (Linux/macOS):** Agent365 offline buffering/replay now requires an explicitly configured, existing, absolute `durableDelivery.storageDirectory`. No automatic Unix temporary-directory fallback or root creation. Missing/invalid roots are logged and disable only disk buffering/replay; online export continues. Customers provision and maintain ownership, permissions (normally a private service-account-owned `0700` root), ACLs, and path-replacement protection; the SDK does not inspect or repair Unix access controls. Windows behavior, explicit-root cache identities, record compatibility, and retention limits are unchanged. Old temporary backlogs are not automatically migrated; see [storage provisioning and migration](A365_DOCUMENTATION.md#storage-provisioning-and-migration).
 
 ### Features Added
diff --git a/package-lock.json b/package-lock.json
index fc2a673ff..57ebf864d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -64,7 +64,7 @@
         "vitest": "^4.1.8"
       },
       "engines": {
-        "node": ">=22.0.0"
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
       }
     },
     "node_modules/@azure-rest/core-client": {
diff --git a/package.json b/package.json
index f61e96d31..78645721e 100644
--- a/package.json
+++ b/package.json
@@ -34,7 +34,7 @@
     ]
   },
   "engines": {
-    "node": ">=22.0.0"
+    "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
   },
   "files": [
     "dist/",
diff --git a/samples/agent365-s2s/package-lock.json b/samples/agent365-s2s/package-lock.json
index df9ce6f62..c1c8c1b96 100644
--- a/samples/agent365-s2s/package-lock.json
+++ b/samples/agent365-s2s/package-lock.json
@@ -18,7 +18,7 @@
         "typescript": "^5.6.0"
       },
       "engines": {
-        "node": ">=22.0.0"
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
       }
     },
     "../..": {
@@ -81,7 +81,7 @@
         "vitest": "^4.1.8"
       },
       "engines": {
-        "node": ">=22.0.0"
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
       }
     },
     "node_modules/@azure/msal-common": {
diff --git a/samples/agent365-s2s/package.json b/samples/agent365-s2s/package.json
index b580fb159..a7f18b145 100644
--- a/samples/agent365-s2s/package.json
+++ b/samples/agent365-s2s/package.json
@@ -5,7 +5,7 @@
   "type": "module",
   "description": "Agent365 service-to-service observability sample",
   "engines": {
-    "node": ">=22.0.0"
+    "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
   },
   "scripts": {
     "build": "npm run clean && tsc -p tsconfig.json",
diff --git a/samples/aks-langchain/Dockerfile b/samples/aks-langchain/Dockerfile
index c3628c573..b90d409be 100644
--- a/samples/aks-langchain/Dockerfile
+++ b/samples/aks-langchain/Dockerfile
@@ -1,4 +1,6 @@
-FROM node:22-bookworm-slim
+FROM node:22.23.4-bookworm-slim
+
+RUN node -e "if (process.versions.node !== '22.23.4') throw new Error('Expected Node.js 22.23.4');"
 
 ENV NODE_ENV=production \
     PORT=3000
diff --git a/samples/aks-langchain/package-lock.json b/samples/aks-langchain/package-lock.json
index 209dc3b13..200ed8e31 100644
--- a/samples/aks-langchain/package-lock.json
+++ b/samples/aks-langchain/package-lock.json
@@ -13,7 +13,7 @@
         "@microsoft/opentelemetry": "1.4.0"
       },
       "engines": {
-        "node": ">=22.0.0"
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
       }
     },
     "node_modules/@azure-rest/core-client": {
diff --git a/samples/aks-langchain/package.json b/samples/aks-langchain/package.json
index 6be1d5f38..3f198387b 100644
--- a/samples/aks-langchain/package.json
+++ b/samples/aks-langchain/package.json
@@ -4,7 +4,7 @@
   "private": true,
   "type": "module",
   "engines": {
-    "node": ">=22.0.0"
+    "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
   },
   "scripts": {
     "start": "node --import ./telemetry.mjs app.mjs"
diff --git a/samples/fabric/package.json b/samples/fabric/package.json
index df09f5570..09c10a229 100644
--- a/samples/fabric/package.json
+++ b/samples/fabric/package.json
@@ -2,6 +2,9 @@
   "name": "fabric-demo",
   "private": true,
   "type": "module",
+  "engines": {
+    "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
+  },
   "scripts": {
     "start": "OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318 node --import @microsoft/opentelemetry/loader app.mjs"
   },
diff --git a/samples/package-lock.json b/samples/package-lock.json
index 65b2399fb..597701945 100644
--- a/samples/package-lock.json
+++ b/samples/package-lock.json
@@ -26,7 +26,7 @@
         "typescript": "~5.9.3"
       },
       "engines": {
-        "node": ">=22.0.0"
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
       }
     },
     "..": {
@@ -89,7 +89,7 @@
         "vitest": "^4.1.8"
       },
       "engines": {
-        "node": ">=22.0.0"
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
       }
     },
     "node_modules/@cfworker/json-schema": {
diff --git a/samples/package.json b/samples/package.json
index 8778b7a6d..0a793707b 100644
--- a/samples/package.json
+++ b/samples/package.json
@@ -4,7 +4,7 @@
   "version": "1.0.0",
   "description": "Microsoft OpenTelemetry distribution samples for TypeScript",
   "engines": {
-    "node": ">=22.0.0"
+    "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
   },
   "scripts": {
     "build": "tsc",
diff --git a/scripts/check-node-version.cjs b/scripts/check-node-version.cjs
new file mode 100644
index 000000000..6afc2fdb4
--- /dev/null
+++ b/scripts/check-node-version.cjs
@@ -0,0 +1,32 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+const requiredNodeVersion = "^22.23.4 || ^24.22.1 || >=26.12.1";
+
+function isPatchedNodeVersion(version) {
+  const match = /^v?(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)$/.exec(version);
+  if (!match) {
+    return false;
+  }
+
+  const [major, minor, patch] = match.slice(1).map(Number);
+  const minimum = { 22: [23, 4], 24: [22, 1], 26: [12, 1] }[major];
+  return (
+    major > 26 ||
+    (minimum !== undefined && (minor > minimum[0] || (minor === minimum[0] && patch >= minimum[1])))
+  );
+}
+
+if (require.main === module) {
+  if (!isPatchedNodeVersion(process.versions.node)) {
+    console.error(
+      `Node.js ${process.versions.node} does not meet the October 21, 2026 security baseline. ` +
+        `Required: ${requiredNodeVersion}. Upgrade the selected Node.js runtime.`,
+    );
+    process.exitCode = 1;
+  } else {
+    console.log(`Node.js ${process.versions.node} meets the October 21, 2026 security baseline.`);
+  }
+}
+
+module.exports = { isPatchedNodeVersion, requiredNodeVersion };
diff --git a/test/integration/node-version.test.mjs b/test/integration/node-version.test.mjs
new file mode 100644
index 000000000..cbbede6b9
--- /dev/null
+++ b/test/integration/node-version.test.mjs
@@ -0,0 +1,117 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+import assert from "node:assert/strict";
+import { spawnSync } from "node:child_process";
+import { readFileSync } from "node:fs";
+import { test } from "node:test";
+import { fileURLToPath } from "node:url";
+import { runInNewContext } from "node:vm";
+import { isPatchedNodeVersion, requiredNodeVersion } from "../../scripts/check-node-version.cjs";
+
+test("accepts the October security releases and subsequent stable versions", () => {
+  for (const version of [
+    "22.23.4",
+    "22.23.5",
+    "22.24.0",
+    "24.22.1",
+    "24.22.2",
+    "24.23.0",
+    "26.12.1",
+    "26.12.2",
+    "26.13.0",
+    "27.0.0",
+    "v22.23.4",
+  ]) {
+    assert.equal(isPatchedNodeVersion(version), true, version);
+  }
+});
+
+test("rejects vulnerable patches, end-of-life lines, and prereleases", () => {
+  for (const version of [
+    "20.99.99",
+    "22.0.0",
+    "22.22.99",
+    "22.23.3",
+    "23.99.99",
+    "24.21.99",
+    "24.22.0",
+    "25.99.99",
+    "26.11.99",
+    "26.12.0",
+    "22.23.4-rc.1",
+    "27.0.0-rc.1",
+    "",
+    "22",
+    "22.23",
+    "022.23.4",
+    "not-a-version",
+  ]) {
+    assert.equal(isPatchedNodeVersion(version), false, version);
+  }
+});
+
+test("checks the running executable, not a supplied version argument or environment override", () => {
+  const script = fileURLToPath(new URL("../../scripts/check-node-version.cjs", import.meta.url));
+  for (const version of ["0.0.0", "99.0.0"]) {
+    const result = spawnSync(process.execPath, [script, version], {
+      encoding: "utf8",
+      env: { ...process.env, NODE_VERSION: version },
+    });
+    assert.ifError(result.error);
+    const expected = isPatchedNodeVersion(process.versions.node) ? 0 : 1;
+    assert.equal(result.status, expected, result.stderr);
+    assert.ok(`${result.stdout}${result.stderr}`.includes(process.versions.node));
+  }
+});
+
+test("reports failure for an old selected runtime even with patched-version overrides", () => {
+  const entry = {};
+  const errors = [];
+  const runtime = {
+    versions: { node: "24.18.0" },
+    argv: ["node", "check-node-version.cjs", "24.22.1"],
+    env: { NODE_VERSION: "24.22.1" },
+  };
+  const script = readFileSync(
+    new URL("../../scripts/check-node-version.cjs", import.meta.url),
+    "utf8",
+  );
+  runInNewContext(script, {
+    require: { main: entry },
+    module: entry,
+    process: runtime,
+    console: {
+      error: (message) => errors.push(message),
+      log: () => assert.fail("Reported success"),
+    },
+  });
+  assert.equal(runtime.exitCode, 1);
+  assert.match(errors[0], /Node\.js 24\.18\.0 does not meet/);
+});
+
+test("keeps repository package and linked lockfile runtime requirements aligned", () => {
+  for (const directory of [
+    "",
+    "samples/",
+    "samples/agent365-s2s/",
+    "samples/aks-langchain/",
+    "samples/fabric/",
+  ]) {
+    const manifest = JSON.parse(
+      readFileSync(new URL(`../../${directory}package.json`, import.meta.url), "utf8"),
+    );
+    assert.equal(manifest.engines.node, requiredNodeVersion, directory || "root");
+    if (directory === "samples/fabric/") {
+      continue;
+    }
+    const lock = JSON.parse(
+      readFileSync(new URL(`../../${directory}package-lock.json`, import.meta.url), "utf8"),
+    );
+    for (const [path, entry] of Object.entries(lock.packages)) {
+      if (path === "" || path === ".." || path === "../..") {
+        assert.equal(entry.engines.node, requiredNodeVersion, `${directory}${path}`);
+      }
+    }
+  }
+});