Inefficient Regular Expression Complexity Affecting actions-runner package, versions <2.331.0-r3


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.48% (38th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-ACTIONSRUNNER-15235961
  • published6 Feb 2026
  • disclosed4 Feb 2026

Introduced: 4 Feb 2026

CVE-2026-25547  (opens in a new tab)
CWE-1333  (opens in a new tab)

How to fix?

Upgrade Chainguard actions-runner to version 2.331.0-r3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream actions-runner package and not the actions-runner package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

@isaacs/brace-expansion is a hybrid CJS/ESM TypeScript fork of brace-expansion. Prior to version 5.0.1, @isaacs/brace-expansion is vulnerable to a denial of service (DoS) issue caused by unbounded brace range expansion. When an attacker provides a pattern containing repeated numeric brace ranges, the library attempts to eagerly generate every possible combination synchronously. Because the expansion grows exponentially, even a small input can consume excessive CPU and memory and may crash the Node.js process. This issue has been patched in version 5.0.1.

CVSS Base Scores

version 3.1