Composer: Perforce source URL permits P4PORT `rsh:` command execution (CVE-2026-84361) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-84361

Composer: Perforce source URL permits P4PORT `rsh:` command execution

Answer in brief

CVE-2026-84361 records a Unknown severity vulnerability in Composer: Perforce source URL permits P4PORT `rsh:` command execution. The current sources do not mark it as known exploited. The current feed maps composer/composer (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 1, 2026Updated Sep 1, 2026Source checked Sep 1, 2026First seen by HOL Sep 1, 2026Material review Sep 1, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps composer/composer (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
composer/composergeneric	>= 1.0, < 2.2.30 \|\| >= 2.3.0, < 2.10.3	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for composer/composer.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 1, 2026

Sources and claim methodology

Upstream source description

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and 2.10.3, a malicious dependency package from a custom Composer repository or an untrusted composer.lock file could set source.type to perforce and source.url to an rsh: or jsh: P4PORT value. When the Perforce p4 client was installed and Composer installed the package from source through composer install or composer update, including --prefer-source, Composer\Util\Perforce passed the address to p4 without validation, causing p4 to run a local command with the privileges of the user or CI account. Packagist.org does not permit Perforce source metadata. This issue is fixed in versions 2.2.30 and 2.10.3.

Quoted source text, attributed separately from HOL analysis.