diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 80d7061..e1ac1fe 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,12 +7,24 @@ on:
 
 jobs:
   release:
-    name: Build
+    name: Build (Node ${{ matrix.node-version }})
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        # The patched floor of each line in package.json engines.node (#58);
+        # tests/node-version.test.ts keeps them equal.
+        node-version: ['22.23.4', '24.22.1', '26.12.1']
     steps:
-      - uses: actions/setup-node@v2
+      - name: 🛎 Checkout
+        uses: actions/checkout@v3
+
+      - uses: actions/setup-node@v4
         with:
-          node-version: 18.19.0
+          node-version: ${{ matrix.node-version }}
+
+      - name: 🔐 TLS probe (eMudhra chain must be rejected)
+        run: node scripts/tls-probe.mjs
       - uses: shogo82148/actions-setup-mysql@v1.23.0
         with:
           mysql-version: '8.0'
@@ -23,9 +35,6 @@ jobs:
       - name: Create test DB
         run: mysql -h localhost -u root -e 'CREATE DATABASE test_db'
 
-      - name: 🛎 Checkout
-        uses: actions/checkout@v3
-
       - name: 🧶 Get NPM cache
         uses: actions/cache@v3
         id: cache-npm
diff --git a/.nvmrc b/.nvmrc
new file mode 100644
index 0000000..ce62013
--- /dev/null
+++ b/.nvmrc
@@ -0,0 +1 @@
+24.22.1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0e0f1c..da1c27f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Security
+
+- Require Node.js `^22.23.4 || ^24.22.1 || >=26.12.1` via `engines.node`. Earlier releases trust TLS chains through the compromised eMudhra intermediates ([nodejs/node#66871](https://github.com/nodejs/node/pull/66871)).
+
 ## [0.9.2]
 
 ### Added
diff --git a/README.md b/README.md
index 3ffe3a4..1154fc7 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,11 @@ An APM solution based on metrics and open-source tools such as Prometheus and Gr
 npm install --save @last9/openapm@latest
 ```
 
+Requires Node.js `^22.23.4 || ^24.22.1 || >=26.12.1`. Earlier releases trust
+TLS chains through the compromised eMudhra intermediates
+([nodejs/node#66871](https://github.com/nodejs/node/pull/66871)), which affects
+the HTTPS calls OpenAPM makes to Last9.
+
 ## Usage
 
 ```js
@@ -277,6 +282,8 @@ to get familiar with the DSL for defining custom metrics.
 
 Make sure you are in the express directory.
 
+- Use the Node.js version in `.nvmrc` (`nvm use`)
+
 - Install packages
 
 ```
diff --git a/package-lock.json b/package-lock.json
index 93791dd..3ab586e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -52,6 +52,7 @@
         "prettier": "2.8.8",
         "prisma": "^5.13.0",
         "react": "^18.2.0",
+        "semver": "^6.3.1",
         "supertest": "^6.3.3",
         "tiny-glob": "^0.2.9",
         "ts-node": "^10.9.1",
@@ -60,6 +61,9 @@
         "typescript": "^5.1.6",
         "vitest": "^0.32.4"
       },
+      "engines": {
+        "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
+      },
       "peerDependencies": {
         "express": "4.x"
       },
diff --git a/package.json b/package.json
index 245d813..88e4135 100644
--- a/package.json
+++ b/package.json
@@ -17,6 +17,9 @@
     "Tushar Choudhari <tushar@last9.io> (https://github.com/chtushar)",
     "Aniket Rao <aniket@last9.io> (https://github.com/anik3tra0)"
   ],
+  "engines": {
+    "node": "^22.23.4 || ^24.22.1 || >=26.12.1"
+  },
   "peerDependencies": {
     "express": "4.x"
   },
@@ -58,6 +61,7 @@
     "prettier": "2.8.8",
     "prisma": "^5.13.0",
     "react": "^18.2.0",
+    "semver": "^6.3.1",
     "supertest": "^6.3.3",
     "tiny-glob": "^0.2.9",
     "ts-node": "^10.9.1",
diff --git a/scripts/tls-probe.mjs b/scripts/tls-probe.mjs
new file mode 100644
index 0000000..c65ae8e
--- /dev/null
+++ b/scripts/tls-probe.mjs
@@ -0,0 +1,34 @@
+// Acceptance probe for #58: this Node runtime must reject a chain through a
+// compromised eMudhra intermediate with CERT_REVOKED (nodejs/node#66871)
+// while still trusting a normal HTTPS endpoint. Exits non-zero otherwise.
+import https from 'node:https';
+
+const BLOCKED = 'https://dv-g3b-emudhra.we-have-a-problem.com/';
+const TRUSTED = 'https://registry.npmjs.org/';
+
+const connect = (url) =>
+  new Promise((resolve) => {
+    const req = https.get(url, { timeout: 15000 }, (res) => {
+      res.resume();
+      resolve({ ok: true, status: res.statusCode });
+    });
+    req.on('timeout', () => req.destroy(new Error('timeout')));
+    req.on('error', (err) =>
+      resolve({ ok: false, code: err.code ?? err.message })
+    );
+  });
+
+const blocked = await connect(BLOCKED);
+const trusted = await connect(TRUSTED);
+
+console.log(`process.version ${process.version}`);
+console.log(`${BLOCKED} ${JSON.stringify(blocked)}`);
+console.log(`${TRUSTED} ${JSON.stringify(trusted)}`);
+
+if (blocked.code !== 'CERT_REVOKED' || !trusted.ok) {
+  console.error(
+    'TLS probe failed: expected CERT_REVOKED for the eMudhra chain and success for the trusted endpoint'
+  );
+  process.exit(1);
+}
+console.log('TLS probe passed');
diff --git a/tests/node-version.test.ts b/tests/node-version.test.ts
new file mode 100644
index 0000000..d6a3032
--- /dev/null
+++ b/tests/node-version.test.ts
@@ -0,0 +1,53 @@
+import { readFileSync } from 'fs';
+import { join } from 'path';
+import semver from 'semver';
+import { describe, expect, test } from 'vitest';
+
+// Node releases before these patches accept TLS chains through the
+// compromised eMudhra intermediates (nodejs/node#66871, issue #58).
+const PATCHED_FLOORS = ['22.23.4', '24.22.1', '26.12.1'];
+const UNPATCHED = [
+  '18.19.0',
+  '20.19.5',
+  '22.23.3',
+  '23.11.1',
+  '24.22.0',
+  '25.9.0',
+  '26.12.0'
+];
+
+const root = join(__dirname, '..');
+const read = (file: string) => readFileSync(join(root, file), 'utf8');
+const engines: string = JSON.parse(read('package.json')).engines?.node ?? '';
+
+const ciNodeVersions = () => {
+  const matrix = read('.github/workflows/build.yml').match(
+    /node-version:\s*\[([^\]]*)\]/
+  );
+  return matrix
+    ? matrix[1].split(',').map((v) => v.trim().replace(/['"]/g, ''))
+    : [];
+};
+
+describe('Node runtime pins', () => {
+  test('engines.node admits each patched floor', () => {
+    for (const version of PATCHED_FLOORS) {
+      expect(semver.satisfies(version, engines), version).toBe(true);
+    }
+  });
+
+  test('engines.node rejects releases without the eMudhra blocklist', () => {
+    expect(engines).not.toBe('');
+    for (const version of UNPATCHED) {
+      expect(semver.satisfies(version, engines), version).toBe(false);
+    }
+  });
+
+  test('CI tests exactly the patched floors', () => {
+    expect(ciNodeVersions()).toEqual(PATCHED_FLOORS);
+  });
+
+  test('.nvmrc pins a CI-tested patched floor', () => {
+    expect(PATCHED_FLOORS).toContain(read('.nvmrc').trim());
+  });
+});