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[ CVE-2026-102277 · Published 28 Sep 2026 ]

brace-expansion: Quadratic-time expansion of the `{a},b}` rewrite causes CPU denial of service

CVSS 5.3 EPSS <1%Fix available

[ Description ]Official description

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to 1.1.21, 2.1.7, 3.0.9, and 5.0.12, the expand function handles untrusted {a},b}-shaped patterns with many trailing closing braces by restarting its scan once for each trailing closing brace. The successive full-input rescans with linear working-string growth cause quadratic CPU time and memory pressure that can block the Node.js event loop. The process eventually recovers, making the impact a recoverable CPU denial of service. This issue is fixed in versions 1.1.21, 2.1.7, 3.0.9, and 5.0.12.

[ Fixes ]Fixes and patches

  • brace-expansion 5.0.12Fixed version · GitHub Advisories · npm package brace-expansion: upgrade to 5.0.12 or later (affected >= 4.0.0, < 5.0.12)
  • brace-expansion 3.0.9Fixed version · GitHub Advisories · npm package brace-expansion: upgrade to 3.0.9 or later (affected >= 3.0.0, < 3.0.9)
  • brace-expansion 2.1.7Fixed version · GitHub Advisories · npm package brace-expansion: upgrade to 2.1.7 or later (affected >= 2.0.0, < 2.1.7)
  • brace-expansion 1.1.21Fixed version · GitHub Advisories · npm package brace-expansion: upgrade to 1.1.21 or later (affected < 1.1.21)

[ Packages ]Affected open-source packages

[ References ]References