XSS in Angular
CVE-2026-88058
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.30, 21.2.22, and 22.1.4, Angular server-side rendering (SSR) in @angular/platform-server serializes ProcessingInstruction DOM nodes inside fallback raw-content elements without escaping matching ancestor closing tags. ProcessingInstruction data escaped greater-than characters but left less-than characters untouched and did not inspect fallback ancestors, so data such as a matching closing tag prematurely terminates noscript, iframe, noembed, or noframes containers. The vulnerable nodes cannot be authored through standard Angular templates; reachability requires application or library code using inject(DOCUMENT).createProcessingInstruction with attacker-controlled data or Renderer2 DOM insertion inside a fallback container. In HTML5 RAWTEXT parsing, the premature close causes subsequent sibling elements to be interpreted as live HTML and enables arbitrary JavaScript execution in a victim's browser. This issue is fixed in versions 20.3.30, 21.2.22, and 22.1.4.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.003 · change: -0.006
Affected products
- Angular — versions <= 19.2.25, >= 20.0.0, < 20.3.30, >= 21.0.0, < 21.2.22
Weakness classification (CWE)
References
- github.com/angular/angular/security/advisories/GHSA-j3r3-mxqp-r2p4 (Exploit, Third Party Advisory)
- github.com/angular/angular/issues/70146 (Patch, Issue Tracking)
- github.com/angular/angular/commit/73d8bbd27cb46495426d4132975a1355b47ad915 (Patch)
- github.com/angular/angular/commit/89b20568dfaee1ec8e0b3bcf1872acdddd2f4fef (Patch)
- github.com/angular/angular/commit/ba3bc47b20b3d12f5eb141ec9c651373ae4d15e8 (Patch)
- github.com/angular/domino/commit/04f987dc08ff3736b427f50941adf1722458528f (Patch)
- github.com/angular/angular/releases/tag/v20.3.30 (Release Notes)
- github.com/angular/angular/releases/tag/v21.2.22 (Release Notes)
- github.com/angular/angular/releases/tag/v22.1.4 (Release Notes)
Frequently asked questions
- What is CVE-2026-88058?
- CVE-2026-88058 is a medium-severity vulnerability in Angular, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-09-10.
- How severe is CVE-2026-88058?
- Medium severity. CVSS v3 base score is 6.1 out of 10.