---
id: CVE-2026-102277
title: >-
  The brace-expansion library generates arbitrary strings containing a common
  prefix and suffix
summary: >-
  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 r…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-400
  - CWE-407
vendor: juliangruber
product: brace-expansion
affected:
  - 'brace-expansion >= 4.0.0, < 5.0.12'
  - 'brace-expansion >= 3.0.0, < 3.0.9'
  - 'brace-expansion >= 2.0.0, < 2.1.7'
  - brace-expansion < 1.1.21
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T21:17:16.300'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102277'
references:
  - url: >-
      https://github.com/juliangruber/brace-expansion/commit/33a5ef17b8d800bbfa8c52b14c39043b6aac1a96
    label: security-advisories@github.com
  - url: >-
      https://github.com/juliangruber/brace-expansion/commit/bdff773f98e5988616b7039cc9b508df5d640b22
    label: security-advisories@github.com
  - url: >-
      https://github.com/juliangruber/brace-expansion/commit/c55e67d8d8b1c56a2474afff15c2891166b2d364
    label: security-advisories@github.com
  - url: >-
      https://github.com/juliangruber/brace-expansion/commit/ffdfa3e3806bed17c0874b8f1439b084de354a7e
    label: security-advisories@github.com
  - url: >-
      https://github.com/juliangruber/brace-expansion/security/advisories/GHSA-q2hr-2g5m-vwhr
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-28T21:20:54.783Z'
---

## Overview

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

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.