Angular i18n vulnerable to Cross-Site Scripting (XSS)
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 1 fixed, 4 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.
Summary
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Versions prior to 21.2.0, 21.1.16, 20.3.17, and 19.2.19 have a cross-Site scripting vulnerability in the Angular internationalization (i18n) pipeline. In ICU messages (International Components for Unicode), HTML from translated content was not properly sanitized and could execute arbitrary JavaScript. Angular i18n typically involves three steps, extracting all messages from an application in the source language, sending the messages to be translated, and then merging their translations back into the final source code. Translations are frequently handled by contracts with specific partner companies, and involve sending the source messages to a separate contractor before receiving final translations for display to the end user. If the returned translations have malicious content, it could be rendered into the application and execute arbitrary JavaScript. When successfully exploited, this vulnerability allows for execution of attacker controlled JavaScript in the application origin. Depending on the nature of the application being exploited this could lead to credential exfiltration and/or page vandalism. Several preconditions apply to the attack. The attacker must compromise the translation file (xliff, xtb, etc.). Unlike most XSS vulnerabilities, this issue is not exploitable by arbitrary users. An attacker must first compromise an application's translation file before they can escalate privileges into the Angular application client. The victim application must use Angular i18n, use one or more ICU messages, render an ICU message, and not defend against XSS via a safe content security policy. Versions 21.2.0, 21.1.6, 20.3.17, and 19.2.19 patch the issue. Until the patch is applied, developers should consider reviewing and verifying translated content received from untrusted third parties before incorporating it in an Angular application, enabling strict CSP controls to block unauthorized JavaScript from executing on the page, and enabling Trusted Types to enforce proper HTML sanitization.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| angular | angular | 21.2.0-next.0 to before 21.2.0; 21.0.0-next.0 to before 21.1.6; 20.0.0-next.0 to before 20.3.17; 19.0.0-next.0 to before 19.2.19; up to 18.2.14 | 21.2.0, 21.1.6, 20.3.17, 19.2.19 | Patch available | CNA |
| — | @angular/core (npm) | 21.2.0-next.0 to before 21.2.0 | 21.2.0 | Patch available | GHSA-prjf-86w9-mfqv |
| — | @angular/core (npm) | 21.0.0-next.0 to before 21.1.6 | 21.1.6 | Patch available | GHSA-prjf-86w9-mfqv |
| — | @angular/core (npm) | 20.0.0-next.0 to before 20.3.17 | 20.3.17 | Patch available | GHSA-prjf-86w9-mfqv |
| — | @angular/core (npm) | 19.0.0-next.0 to before 19.2.19 | 19.2.19 | Patch available | GHSA-prjf-86w9-mfqv |
| — | @angular/core (npm) | up to 18.2.14 | — | No fix listed | GHSA-prjf-86w9-mfqv |
- angular Vendorangular Affected 21.2.0-next.0 to before 21.2.0; 21.0.0-next.0 to before 21.1.6; 20.0.0-next.0 to before 20.3.17; 19.0.0-next.0 to before 19.2.19; up to 18.2.14 Fixed in 21.2.0, 21.1.6, 20.3.17, 19.2.19 Patch available CNA
- @angular/core (npm) Vendor— Affected 21.2.0-next.0 to before 21.2.0 Fixed in 21.2.0 Patch available GHSA-prjf-86w9-mfqv
- @angular/core (npm) Vendor— Affected 21.0.0-next.0 to before 21.1.6 Fixed in 21.1.6 Patch available GHSA-prjf-86w9-mfqv
- @angular/core (npm) Vendor— Affected 20.0.0-next.0 to before 20.3.17 Fixed in 20.3.17 Patch available GHSA-prjf-86w9-mfqv
- @angular/core (npm) Vendor— Affected 19.0.0-next.0 to before 19.2.19 Fixed in 19.2.19 Patch available GHSA-prjf-86w9-mfqv
- @angular/core (npm) Vendor— Affected up to 18.2.14 Fixed in — No fix listed GHSA-prjf-86w9-mfqv
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:angular:angular:*:*:*:*:*:node.js:*:* | before 19.2.19; 20.0.0 to before 20.3.17; 21.0.0 to before 21.1.6 | Vulnerable | angular |
| cpe:2.3:a:angular:angular:21.2.0:next0:*:*:*:node.js:*:* | 21.2.0 next0 | Vulnerable | angular |
| cpe:2.3:a:angular:angular:21.2.0:next1:*:*:*:node.js:*:* | 21.2.0 next1 | Vulnerable | angular |
| cpe:2.3:a:angular:angular:21.2.0:next2:*:*:*:node.js:*:* | 21.2.0 next2 | Vulnerable | angular |
| cpe:2.3:a:angular:angular:21.2.0:next3:*:*:*:node.js:*:* | 21.2.0 next3 | Vulnerable | angular |
| cpe:2.3:a:angular:angular:21.2.0:rc0:*:*:*:node.js:*:* | 21.2.0 rc0 | Vulnerable | angular |
- cpe:2.3:a:angular:angular:*:*:*:*:*:node.js:*:* Versions before 19.2.19; 20.0.0 to before 20.3.17; 21.0.0 to before 21.1.6 Vulnerable ·angular
- cpe:2.3:a:angular:angular:21.2.0:next0:*:*:*:node.js:*:* Versions 21.2.0 next0 Vulnerable ·angular
- cpe:2.3:a:angular:angular:21.2.0:next1:*:*:*:node.js:*:* Versions 21.2.0 next1 Vulnerable ·angular
- cpe:2.3:a:angular:angular:21.2.0:next2:*:*:*:node.js:*:* Versions 21.2.0 next2 Vulnerable ·angular
- cpe:2.3:a:angular:angular:21.2.0:next3:*:*:*:node.js:*:* Versions 21.2.0 next3 Vulnerable ·angular
- cpe:2.3:a:angular:angular:21.2.0:rc0:*:*:*:node.js:*:* Versions 21.2.0 rc0 Vulnerable ·angular
Remediation
- Fix · CNA angular (angular) Fixed in 21.2.0, 21.1.6, 20.3.17, 19.2.19
- Fix · GHSA-prjf-86w9-mfqv @angular/core (npm) Fixed in 21.2.0 Advisory →
- Fix · GHSA-prjf-86w9-mfqv @angular/core (npm) Fixed in 21.1.6 Advisory →
- Fix · GHSA-prjf-86w9-mfqv @angular/core (npm) Fixed in 20.3.17 Advisory →
- Fix · GHSA-prjf-86w9-mfqv @angular/core (npm) Fixed in 19.2.19 Advisory →
Red Hat 1 advisory
- RHSA-2026:86618 Released 2026-10-21 · Red Hat rating CriticalNew container image: rhceph-9.2
- Red Hat Ceph Storage 9.2 registry.redhat.io/rhceph/rhceph-9-rhel10
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Fuse 7 | Affected | No fix planned: Will not fix |
| Red Hat Ceph Storage 9.2 | Fixed | RHSA-2026:86618 |
Not affected: 7 products
- Red Hat Advanced Cluster Management for Kubernetes 2
- Red Hat Ceph Storage 9.2
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift AI (RHOAI)
Timeline
- 2026-10-02 Threatist record created from CVE-2026-27970
- 2026-10-03 Alias added: GHSA-prjf-86w9-mfqv
- 2026-10-21 Fix available: RHSA-2026:86618 · Red Hat
- 2026-10-21 Fix available: Red Hat Ceph Storage 9.2 · Red Hat
References
Patch 5
- https://github.com/angular/angular/security/advisories/GHSA-prjf-86w9-mfqv
- https://github.com/angular/angular/pull/67183
- https://github.com/angular/angular/commit/306f367899dfc2e04238fecd3455547b5d54075d
- https://github.com/angular/angular/commit/7d58b798c626bb0e4e5f89ca8affdce4f352b232
- https://github.com/angular/angular/commit/b85830953281ff3a1a77bbfe69019d352d509c93
More Angular vulnerabilities
- TI-2026-60076 Angular: SSRF and Cross-Origin Credential Disclosure via URL Resolution Discrepancy in SSR CVSS 4.0HIGH 8.6
- TI-2026-60080 Angular: SSR XSS via Unescaped <template> Content Across DocumentFragment Boundaries in Fallback Raw-Content Elements CVSS 4.0HIGH 8.6
- TI-2026-60078 Angular: SSR XSS via Unescaped Processing Instruction (<?...?>) Nodes in Fallback Raw-Content Elements CVSS 4.0HIGH 8.6
- TI-2025-37971 A reflected cross-site scripting (XSS) vulnerability in CKeditor v46.1.0 & Angular… CVSS 3.1MEDIUM 5.4
- TI-2026-36931 Angular: URL Parser Differential in @angular/platform-server leading to SSRF Allowlist Bypass CVSS 4.0HIGH 8.8
- TI-2026-34131 Angular: SSRF via Hostname Hijacking in @angular/platform-server CVSS 4.0HIGH 8.8
Sources
- CVE-2026-27970 · CVE Program
- CVE-2026-27970 · NVD
- FIRST EPSS
- GHSA-prjf-86w9-mfqv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-27970 · Red Hat security data · CC BY 4.0
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