CVE-2026-40261HIGH 8.8EPSS p74.8%

CVE-2026-40261CVE-2026-40261

getcomposer / composer

Description

Composer is a dependency manager for PHP. Versions 1.0 through 2.2.26 and 2.3 through 2.9.5 contain a command injection vulnerability in the Perforce::syncCodeBase() method, which appends the $sourceReference parameter to a shell command without proper escaping, and additionally in the Perforce::generateP4Command() method as in GHSA-wg36-wvj6-r67p / CVE-2026-40176, which interpolates user-supplied Perforce connection parameters (port, user, client) from the source url field without proper escaping. An attacker can inject arbitrary commands through crafted source reference or source url values containing shell metacharacters, even if Perforce is not installed. Unlike CVE-2026-40176, the source reference and url are provided as part of package metadata, meaning any compromised or malicious Composer repository can serve package metadata declaring perforce as a source type with malicious values. This vulnerability is exploitable when installing or updating dependencies from source, includi

Scoring

CVSS 3.18.8 (HIGH)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS1.69% probability of exploitation · percentile 74.8% · 2026-08-03T12:00:16Z
Published2026-04-15
Last modified2026-07-15

Underlying weaknesses· 2

CWE-20CWE-78

References

  1. https://github.com/composer/composer/releases/tag/2.9.6
  2. https://github.com/composer/composer/security/advisories/GHSA-gqw4-4w2p-838q

2

TypeTargetConfidenceTier
WeaknessImproper Input Validationcwe-200%live
WeaknessImproper Neutralization of Special Elements used in an OS Command ('OS Command Injection')cwe-780%live

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Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.