GHSA-gqw4-4w2p-838q
HIGHGHSA-gqw4-4w2p-838q is a high-severity (CVSS 8.8) vulnerability in composer/composer. O3 Security confirms whether GHSA-gqw4-4w2p-838q is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Composer has a command injection via malicious perforce reference
Blast Radius
composer/composer🐘composer/composerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The Perforce::syncCodeBase() method appended the $sourceReference parameter to a shell command without proper escaping, allowing an attacker to inject arbitrary commands through a crafted source reference containing shell metacharacters. Further as in GHSA-wg36-wvj6-r67p / CVE-2026-40176 the Perforce::generateP4Command() method constructed shell commands by interpolating user-supplied Perforce connection parameters (port, user, client) without proper escaping from the source url field. Composer would execute these injected commands even if Perforce is not installed.
The source reference and url are provided as part of package metadata. Any Composer package repository can serve package metadata declaring perforce as a source type with a malicious source reference or source url. This means the vulnerability can be exploited through any package served by a compromised or malicious Composer repository. An attack does not require Perforce to be installed on the client, as Composer will attempt to execute the constructed command regardless.
This vulnerability is exploitable when installing or updating dependencies from source (--prefer-source, default when installing dev prefixed versions), even if you do not use Perforce.
Patches
Fixed in Composer 2.2.27 (2.2 LTS) and 2.9.6 (mainline)
Note, the fix for the source url in the Perforce::generateP4Command() was addressed as part of the patches for GHSA-wg36-wvj6-r67p / CVE-2026-40176 in the same versions.
Workarounds
- Avoid installing dependencies from source by using
--prefer-distor thepreferred-install: distconfig setting. - Only use trusted Composer repositories.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | composer/composer | ≥ 2.3.0&&< 2.9.6 | 2.9.6 |
| 🐘Packagist | composer/composer | ≥ 1.0.0&&< 2.2.27 | 2.2.27 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for composer/composer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update composer/composer to 2.9.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gqw4-4w2p-838q is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-gqw4-4w2p-838q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-gqw4-4w2p-838q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-gqw4-4w2p-838q in your dependencies?
O3 detects GHSA-gqw4-4w2p-838q across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.