CVE-2026-102277

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

Published Sep 28, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Github GHSA Github GHSA GHSA-q2hr-2g5m-vwhr brace-expansion: Quadratic-time expansion of the `{a},b}` rewrite causes CPU denial of service
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Juliangruber
Juliangruber brace-expansion
Vendors & Products Juliangruber
Juliangruber brace-expansion
Type Values Removed Values Added
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.
Title brace-expansion: Quadratic-time expansion of the `{a},b}` rewrite causes CPU denial of service
Weaknesses CWE-400
CWE-407
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 29, 2026, 7:38 PM
Reserved
Sep 28, 2026, 8:11 PM
Status
Deferred
Published
Sep 28, 2026, 9:17 PM
Modified
Sep 30, 2026, 7:57 PM
Severity
Moderate
Public date
Sep 28, 2026, 8:54 PM