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[ CVE-2026-101895 · Published 14 Oct 2026 ]

Angular SSR: Denial of Service (DoS) via Infinite Loop on Malformed DOCTYPE

CVSS 8.7 EPSS <1%1 agency advisoryFix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.31, 21.2.23, and 22.1.6, the @angular/platform-server DOM emulation parser can enter an infinite synchronous loop when Angular server-side rendering processes attacker-controlled HTML containing an incomplete DOCTYPE that ends with whitespace at end of input. In Domino lib/HTMLParser.js, after_doctype_name_state emits doctype and EOF tokens without advancing nextchar or leaving the fixed-lookahead state, so the scanner repeatedly handles the same EOF marker. A remote unauthenticated attacker can use this condition through server-side HTML parsing paths such as innerHTML binding to consume a Node.js SSR worker at full CPU, starve the event loop, and stop concurrent and subsequent requests. This issue is fixed in versions 20.3.31, 21.2.23, and 22.1.6.

[ Fixes ]Fixes and patches

  • @angular/platform-server 22.1.6Fixed version · GitHub Advisories · npm package @angular/platform-server: upgrade to 22.1.6 or later (affected >= 22.0.0, < 22.1.6)
  • @angular/platform-server 21.2.23Fixed version · GitHub Advisories · npm package @angular/platform-server: upgrade to 21.2.23 or later (affected >= 21.0.0, < 21.2.23)
  • @angular/platform-server 20.3.31Fixed version · GitHub Advisories · npm package @angular/platform-server: upgrade to 20.3.31 or later (affected >= 20.0.0, < 20.3.31)

[ Advisories ]Government CERT advisories

[ Packages ]Affected open-source packages

[ References ]References