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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-102277
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-28 21:17:16 UTC
Updated2026-09-30 19:57:08 UTC
DescriptionThe 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.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS: 0.003010000 probability, percentile 0.205350000 (date 2026-09-29)

Problem Types: CWE-400 | CWE-407 | CWE-400 CWE-400: Uncontrolled Resource Consumption | CWE-407 CWE-407: Inefficient Algorithmic Complexity

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Juliangruber Brace-expansion affected >= 4.0.0, < 5.0.12 Not specified
CNA Juliangruber Brace-expansion affected >= 3.0.0, < 3.0.9 Not specified
CNA Juliangruber Brace-expansion affected >= 2.0.0, < 2.1.7 Not specified
CNA Juliangruber Brace-expansion affected < 1.1.21 Not specified

References

ReferenceSourceLinkTags
github.com/juliangruber/brace-expansion/commit/c55e67d8d8b1c56a2474afff1... [email protected] github.com
github.com/juliangruber/brace-expansion/commit/33a5ef17b8d800bbfa8c52b14... [email protected] github.com
github.com/juliangruber/brace-expansion/security/advisories/GHSA-q2hr-2g... [email protected] github.com
github.com/juliangruber/brace-expansion/commit/ffdfa3e3806bed17c0874b8f1... [email protected] github.com
github.com/juliangruber/brace-expansion/commit/bdff773f98e5988616b7039cc... [email protected] github.com
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