GHSA-jj27-h5hq-8x99 — @angular/compiler
Fix: angular/angular#68821GHSA-jj27-h5hq-8x99 is a Cross-site Scripting (XSS) vulnerability in @angular/compiler. A fix is available for @angular/compiler — see the affected versions and patch details below.
Angular i18n: Cross-Site Scripting (XSS) via event-handler attributes
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-jj27-h5hq-8x99.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@angular/compilernpmDescription
A Cross-Site Scripting (XSS) vulnerability has been identified in the Angular compiler's internationalization (i18n) pipeline. Although Angular disallows binding to event-handler attributes such as onclick and onerror through standard attribute validation (validateAttribute() / validateProperty()), the i18n metadata collection path allowed these same attribute names to be marked for translation using i18n-on* attributes (e.g., i18n-onerror).
When exploited, a lower-trust translation file could replace a benign static handler such as onerror="void 0" with arbitrary executable JavaScript in the localized build.
The following example illustrates a vulnerable pattern:
<img src="foo.jpg" onerror="void 0" i18n-onerror />
Impact
When exploited, this vulnerability allows arbitrary JavaScript execution within the context of the vulnerable application's domain if an attacker can control or influence the translation files used during localization. This can lead to:
- Session Hijacking: Accessing session cookies, tokens, or sensitive user data.
- Unauthorized Actions: Performing actions on behalf of the authenticated user.
Patched Versions
- 22.0.1
- 21.2.19
- 20.3.27
Workarounds
Ensure that static event-handler attributes (e.g., onerror, onclick) are never marked for internationalization (i18n-on*) in application templates, and ensure translation files are sourced from trusted origins.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @angular/compiler | ≥ 22.0.0-next.0&&< 22.0.1 | 22.0.1npm install @angular/compiler@22.0.1 |
| 📦npm | @angular/compiler | ≥ 21.0.0-next.0&&< 21.2.19 | 21.2.19npm install @angular/compiler@21.2.19 |
| 📦npm | @angular/compiler | ≥ 20.0.0-next.0&&< 20.3.27 | 20.3.27npm install @angular/compiler@20.3.27 |
| 📦npm | @angular/compiler | all versions | No fix |
| 📦npm | @angular/core | ≥ 22.0.0-next.0&&< 22.0.1 | 22.0.1npm install @angular/core@22.0.1 |
| 📦npm | @angular/core | ≥ 21.0.0-next.0&&< 21.2.19 | 21.2.19npm install @angular/core@21.2.19 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @angular/compiler, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @angular/compiler to 22.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jj27-h5hq-8x99 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-jj27-h5hq-8x99 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-jj27-h5hq-8x99. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-jj27-h5hq-8x99 in your dependencies?
O3 Security finds GHSA-jj27-h5hq-8x99 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.