- 7.8HighCVSS base score
- 1.0%Exploitation in 30 daysEPSS · top 35% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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::generateP4Command() method, which constructs shell commands by interpolating user-supplied Perforce connection parameters (port, user, client) without proper escaping. An attacker can inject arbitrary commands through these values in a malicious composer.json declaring a Perforce VCS repository, leading to command execution in the context of the user running Composer, even if Perforce is not installed. VCS repositories are only loaded from the root composer.json or the composer config directory, so this cannot be exploited through composer.json files of packages installed as dependencies. Users are at risk if they run Composer commands on untrusted projects with attacker-supplied composer.json files. This issue has been fixed in Composer 2.2.27 (2.2 LTS) and 2.9.6 (mainline).
Timeline
ID reserved
By GitHub_M
- 6 days later
· 6 days later
Published
- 7 months later
· 7 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| redhat-SADPADP (enrichment) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.0% · top 35% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Packagistcomposer/composerGHSA-wg36-wvj6-r67p (opens in a new tab)
References
References8
- https://github.com/composer/composer/security/advisories/GHSA-wg36-wvj6-r67p (opens in a new tab)x_refsource_CONFIRM
- https://access.redhat.com/errata/RHSA-2026:8165 (opens in a new tab)x_refsource_MISCvendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-40176 (opens in a new tab)x_refsource_MISCvdb-entryx_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2458828 (opens in a new tab)x_refsource_MISCissue-trackingx_refsource_REDHAT
- https://github.com/FriendsOfPHP/security-advisories/blob/master/composer/composer/CVE-2026-40176.yaml (opens in a new tab)x_refsource_MISC
- https://github.com/composer/composer/releases/tag/2.2.27 (opens in a new tab)x_refsource_MISC
- https://github.com/composer/composer/releases/tag/2.9.6 (opens in a new tab)x_refsource_MISC
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40176.json (opens in a new tab)x_refsource_MISCx_sadp-csaf-vex
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-23118 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-wg36-wvj6-r67p (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-40176)Record last updated .