diff --git a/web/src/compositions/usePipeline.ts b/web/src/compositions/usePipeline.ts
index 61142149d3..a566a97424 100644
--- a/web/src/compositions/usePipeline.ts
+++ b/web/src/compositions/usePipeline.ts
@@ -6,6 +6,7 @@ import { useI18n } from 'vue-i18n';
 import { useDate } from '~/compositions/useDate';
 import { useElapsedTime } from '~/compositions/useElapsedTime';
 import type { Pipeline } from '~/lib/api/types';
+import { escapeHtml } from '~/lib/utils';
 
 const { toLocaleString, timeAgo, prettyDuration } = useDate();
 
@@ -75,10 +76,10 @@ export default (pipeline: Ref<Pipeline | undefined>) => {
     return prettyDuration(durationElapsed.value);
   });
 
-  const message = computed(() => emojify(pipeline.value?.message ?? ''));
+  const message = computed(() => emojify(escapeHtml(pipeline.value?.message ?? '')));
   const shortMessage = computed(() => message.value.split('\n')[0]);
 
-  const prTitleWithDescription = computed(() => emojify(pipeline.value?.title ?? ''));
+  const prTitleWithDescription = computed(() => emojify(escapeHtml(pipeline.value?.title ?? '')));
   const prTitle = computed(() => prTitleWithDescription.value.split('\n')[0]);
 
   const prettyRef = computed(() => {
diff --git a/web/src/lib/utils.test.ts b/web/src/lib/utils.test.ts
new file mode 100644
index 0000000000..707b2a009b
--- /dev/null
+++ b/web/src/lib/utils.test.ts
@@ -0,0 +1,45 @@
+import { describe, expect, it } from 'vitest';
+
+import { escapeHtml } from './utils';
+
+describe('escapeHtml', () => {
+  it('should return plain text unchanged', () => {
+    expect(escapeHtml('hello world')).toBe('hello world');
+  });
+
+  it('should return empty string unchanged', () => {
+    expect(escapeHtml('')).toBe('');
+  });
+
+  it('should escape HTML tags', () => {
+    expect(escapeHtml('<b>bold</b>')).toBe('&lt;b&gt;bold&lt;/b&gt;');
+    expect(escapeHtml('<script>alert("xss")</script>')).toBe('&lt;script&gt;alert(&quot;xss&quot;)&lt;/script&gt;');
+  });
+
+  it('should escape ampersands', () => {
+    expect(escapeHtml('foo & bar')).toBe('foo &amp; bar');
+    expect(escapeHtml('a&&b')).toBe('a&amp;&amp;b');
+  });
+
+  it('should escape double quotes', () => {
+    expect(escapeHtml('say "hello"')).toBe('say &quot;hello&quot;');
+  });
+
+  it('should escape single quotes', () => {
+    expect(escapeHtml("it's")).toBe('it&#x27;s');
+  });
+
+  it('should escape greater-than signs', () => {
+    expect(escapeHtml('a > b')).toBe('a &gt; b');
+  });
+
+  it('should escape mixed content', () => {
+    expect(escapeHtml(`<a href="foo">it's & that's <b>all</b>`)).toBe(
+      '&lt;a href=&quot;foo&quot;&gt;it&#x27;s &amp; that&#x27;s &lt;b&gt;all&lt;/b&gt;',
+    );
+  });
+
+  it('should escape already-escaped ampersands', () => {
+    expect(escapeHtml('&amp;')).toBe('&amp;amp;');
+  });
+});
diff --git a/web/src/lib/utils/index.ts b/web/src/lib/utils/index.ts
index 5340d52a20..dfe7b6c1a3 100644
--- a/web/src/lib/utils/index.ts
+++ b/web/src/lib/utils/index.ts
@@ -11,3 +11,12 @@ export function debounce<T extends unknown[]>(fn: (...args: T) => void, delay: n
 export function deepClone<T>(value: T): T {
   return JSON.parse(JSON.stringify(toRaw(value))) as T;
 }
+
+export function escapeHtml(text: string): string {
+  return text
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#x27;');
+}