CVE-2026-88058 — Angular: SSR XSS via Unescaped Processing Instruction (<?...?>) Nodes in Fallback Raw-Content Elements
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, Angula…
Published: 2026-09-10 · CVSS: 8.6 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7