diff --git a/__tests__/github/summary.test.ts b/__tests__/github/summary.test.ts
new file mode 100644
index 00000000..62bd1e2b
--- /dev/null
+++ b/__tests__/github/summary.test.ts
@@ -0,0 +1,58 @@
+/**
+ * Copyright 2026 actions-toolkit authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {afterEach, describe, expect, test, vi} from 'vitest';
+import * as core from '@actions/core';
+
+import {GitHubSummary} from '../../src/github/summary.js';
+
+afterEach(() => {
+  core.summary.emptyBuffer();
+  vi.restoreAllMocks();
+});
+
+describe('writeBuildSummary', () => {
+  test.each([1, 11])('escapes a build error with %i lines', async lines => {
+    const error = Array(lines).fill('unknown instruction: <tag> & value').join('\n');
+    const encodedError = Array(lines).fill('unknown instruction: &#x3C;tag&#x3E; &#x26; value').join('\n');
+    const write = vi.spyOn(core.summary, 'write').mockResolvedValue(core.summary);
+
+    await GitHubSummary.writeBuildSummary({
+      exportRes: {
+        dockerbuildFilename: 'build.dockerbuild',
+        dockerbuildSize: 0,
+        builderName: 'builder',
+        nodeName: 'node',
+        refs: ['buildref'],
+        summaries: {
+          buildref: {
+            name: 'build',
+            status: 'failed',
+            duration: '1s',
+            numCachedSteps: 0,
+            numTotalSteps: 1,
+            numCompletedSteps: 0,
+            error
+          }
+        }
+      }
+    });
+
+    expect(write).toHaveBeenCalledOnce();
+    expect(core.summary.stringify()).toContain(`<pre lang="text"><code>${encodedError}</code></pre>`);
+    expect(core.summary.stringify().includes('<details><summary><strong>Error</strong></summary>')).toBe(lines > 10);
+  });
+});
diff --git a/package.json b/package.json
index 272b67ac..bc62f3e3 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "csv-parse": "^7.0.3",
     "gunzip-maybe": "^1.4.2",
     "handlebars": "^4.7.10",
-    "he": "^1.2.0",
+    "he": "^2.0.0",
     "js-yaml": "^5.4.3",
     "jwt-decode": "^4.0.0",
     "semver": "^7.8.5",
diff --git a/src/github/summary.ts b/src/github/summary.ts
index 9da84419..ac4e453f 100644
--- a/src/github/summary.ts
+++ b/src/github/summary.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import he from 'he';
+import * as he from 'he';
 import {dump as yamldump} from 'js-yaml';
 import os from 'os';
 import * as core from '@actions/core';
diff --git a/yarn.lock b/yarn.lock
index b1a98b83..e0ff11a3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -502,7 +502,7 @@ __metadata:
     globals: "npm:^17.3.0"
     gunzip-maybe: "npm:^1.4.2"
     handlebars: "npm:^4.7.10"
-    he: "npm:^1.2.0"
+    he: "npm:^2.0.0"
     js-yaml: "npm:^5.4.3"
     jwt-decode: "npm:^4.0.0"
     prettier: "npm:^3.8.1"
@@ -3138,12 +3138,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"he@npm:^1.2.0":
-  version: 1.2.0
-  resolution: "he@npm:1.2.0"
+"he@npm:^2.0.0":
+  version: 2.0.0
+  resolution: "he@npm:2.0.0"
   bin:
-    he: bin/he
-  checksum: 10/d09b2243da4e23f53336e8de3093e5c43d2c39f8d0d18817abfa32ce3e9355391b2edb4bb5edc376aea5d4b0b59d6a0482aab4c52bc02ef95751e4b818e847f1
+    he: bin/he.mjs
+  checksum: 10/f554704a474bf74e169f7420ec23d4c21dadfdc5b0d88e8de35d24b6610bb177fb189bd6dfc10caae35edac0df2e79c8778a90d59ae3718a50b00f3bdd544999
   languageName: node
   linkType: hard