XSS in Angular

CVE-2025-66412

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 21.0.2, 20.3.15, and 19.2.17, A Stored Cross-Site Scripting (XSS) vulnerability has been identified in the Angular Template Compiler. It occurs because the compiler's internal security schema is incomplete, allowing attackers to bypass Angular's built-in security sanitization. Specifically, the schema fails to classify certain URL-holding attributes (e.g., those that could contain javascript: URLs) as requiring strict URL security, enabling the injection of malicious scripts. This vulnerability is fixed in 21.0.2, 20.3.15, and 19.2.17.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-66412: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • Angular — versions >= 21.0.0-next.0 < 21.0.2, >= 20.0.0-next.0 < 20.3.15, >= 19.0.0-next.0 < 19.2.17

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-66412?
CVE-2025-66412 is a medium-severity vulnerability in Angular, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-12-01.
How severe is CVE-2025-66412?
Medium severity. CVSS v3 base score is 5.4 out of 10.