# CVE-2026-27970: Google Angular XSS in internationalization ICU messages

Source: https://junglewise.ai/threats/cve-2026-27970-google-angular-xss-in-internationalization-icu-messages  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-26. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-27970 · Severity: medium · CVSS 6.1 · Published 2026-02-26

Angular is a popular development framework used to build web and mobile applications. A security flaw in its translation system could allow malicious code to be injected into an application if its translation files (used for different languages) are tampered with. If exploited, this could allow an attacker to steal user credentials, access sensitive data, or deface the website.

Technologies: [@angular/core (npm)](https://junglewise.ai/threats/technologies/angular-core). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-27970 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-27970 being exploited in the wild.

**How severe is CVE-2026-27970?** Medium severity, with a CVSS score of 6.1, published 26 February 2026.

**Which products and versions are affected?** @angular/core (npm) SEMVER:introduced=21.2.0-next.0,fixed=21.2.0.

**Is there a fix for CVE-2026-27970?** Yes. @angular/core (npm): upgrade to 21.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-27970 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-27970?** Check whether you run @angular/core (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @angular/core (npm): upgrade to 21.2.0 or later

  ```sh
  npm install @angular/core@21.2.0
  ```


## Technical details

A cross-site scripting (XSS) vulnerability exists in the Angular internationalization (i18n) pipeline due to improper sanitization of HTML within International Components for Unicode (ICU) messages. The vulnerability occurs during the 'merge' phase of the i18n workflow, where translated content is integrated back into the application. If an attacker compromises the translation source files (such as .xliff or .xtb files), they can inject malicious HTML/JavaScript that executes in the context of the application origin. Exploitation requires the application to use Angular i18n with ICU messages and lacks a restrictive Content Security Policy (CSP). The fix introduces an allowlist for HTML attributes in translated ICU content and blocks sensitive URI attributes.

## Affected products

- Google Angular < 21.2.0, < 21.1.6, < 20.3.17, < 19.2.19, <= 18.2.14

## Identifiers

- CVE-2026-27970
- GHSA-prjf-86w9-mfqv

## Timeline

- 2026-02-20: other: Fix pull request submitted
- 2026-02-24: patched: Fix merged into main branch
- 2026-02-25: advisory: GitHub Security Advisory published
- 2026-02-26: disclosed: CVE published to NVD

## References

- [https://github.com/angular/angular/commit/306f367899dfc2e04238fecd3455547b5d54075d](https://github.com/angular/angular/commit/306f367899dfc2e04238fecd3455547b5d54075d)
- [https://github.com/angular/angular/commit/7d58b798c626bb0e4e5f89ca8affdce4f352b232](https://github.com/angular/angular/commit/7d58b798c626bb0e4e5f89ca8affdce4f352b232)
- [https://github.com/angular/angular/commit/b85830953281ff3a1a77bbfe69019d352d509c93](https://github.com/angular/angular/commit/b85830953281ff3a1a77bbfe69019d352d509c93)
- [https://github.com/angular/angular/pull/67183](https://github.com/angular/angular/pull/67183)
- [https://github.com/angular/angular/security/advisories/GHSA-prjf-86w9-mfqv](https://github.com/angular/angular/security/advisories/GHSA-prjf-86w9-mfqv)
- [https://access.redhat.com/security/cve/CVE-2026-27970](https://access.redhat.com/security/cve/CVE-2026-27970)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2442934](https://bugzilla.redhat.com/show_bug.cgi?id=2442934)

## Related threats

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- [Google Angular DOM Clobbering in Client Hydration](https://junglewise.ai/threats/cve-2026-54267-google-angular-dom-clobbering-in-client-hydration)
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- [Google Angular XSS bypass via namespaced elements and attributes](https://junglewise.ai/threats/cve-2026-50557-google-angular-xss-bypass-via-namespaced-elements-and-attributes)