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vulnerability / NVI-00005281 / Revision 3

Composer arbitrary command execution via a malicious package's Perforce source URL

OSV carries this publisher advisory for composer/composer, composer/composer. This is an aggregated source copy; consult the original publisher and compare update dates.

source listedactiveGHSA-rvx4-ffvw-m9q3CVE-2026-84361

This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.

01 / Meaning

Why it matters

Published affected context helps an owner decide what evidence to gather. This report has not examined your application.

EPSS

0.502%

FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.43005. Missing scores are unknown.

As of · FIRST EPSS

02 / Applicability

The affected context

Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.

composer/composer

source listed
  • ECOSYSTEM: introduced 2.3.0; fixed 2.10.3

## Summary If the `p4` Perforce CLI client is installed, a malicious dependency package from a package repository allowing arbitrary perforce source URLs (packagist.org is safe) could execute arbitrary commands when running `composer install` or `composer update`. Composer passed a package's Perforce source address to the `p4` CLI client without validating it. The `p4` CLI client accepts addresses that mean "run this local command" instead of "connect to this server". This is remote code execution with the privileges of the user or CI account running Composer. ## Am I affected? You are only affected if all of the following are true: - The Perforce `p4` command line client is installed and on the `PATH` of the machine running Composer. - An attacker can control a package metadata's `source` section with a perforce type. Packagist.org does not allow perforce source metadata, so you are only exploitable if you rely on another Composer repository (any custom `composer`-type repository, or an inline `package` repository entry), or a `composer.lock` file you obtained from somewhere you do not trust. - The package gets installed from source, either because it has no dist artifact or b

GitHub Advisory Database via OSV

composer/composer

source listed
  • ECOSYSTEM: introduced 1.0; fixed 2.2.30

## Summary If the `p4` Perforce CLI client is installed, a malicious dependency package from a package repository allowing arbitrary perforce source URLs (packagist.org is safe) could execute arbitrary commands when running `composer install` or `composer update`. Composer passed a package's Perforce source address to the `p4` CLI client without validating it. The `p4` CLI client accepts addresses that mean "run this local command" instead of "connect to this server". This is remote code execution with the privileges of the user or CI account running Composer. ## Am I affected? You are only affected if all of the following are true: - The Perforce `p4` command line client is installed and on the `PATH` of the machine running Composer. - An attacker can control a package metadata's `source` section with a perforce type. Packagist.org does not allow perforce source metadata, so you are only exploitable if you rely on another Composer repository (any custom `composer`-type repository, or an inline `package` repository entry), or a `composer.lock` file you obtained from somewhere you do not trust. - The package gets installed from source, either because it has no dist artifact or b

GitHub Advisory Database via OSV

03 / Response

What to do next

  1. vendor patch

    The original advisory lists fixed boundaries 2.10.3 for composer/composer. Confirm the publisher’s latest guidance.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV

  2. vendor patch

    The original advisory lists fixed boundaries 2.2.30 for composer/composer. Confirm the publisher’s latest guidance.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV

  3. investigate

    Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS

A fixed release is not deployment evidence.

Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.

04 / Limits

What this report cannot establish

  • Customer inventory, deployment, reachability and exploitation have not been inspected.
  • NVD lastModified does not establish freshness of every associated CPE record.
Read the collection and interpretation limits ↗

05 / Provenance

Sources you can inspect

Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.

  1. GHSA-rvx4-ffvw-m9q3 ↗

    GitHub Advisory Database via OSV · vendor advisory

    Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.

  2. CVE-2026-84361 ↗

    NIST National Vulnerability Database · official catalog

    Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.

  3. CVE-2026-84361 ↗

    FIRST EPSS · official catalog

    Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.

Public revision history

Only published revisions appear here. Routine fetches do not create a material-change event.

  1. Revision 3 ·

    Source facts changed; compare the preserved prior revision.

  2. Revision 2 ·

    Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.

Read the public revision data ↗

The next step is private

Bring the question into your environment.

The connected workflow is a development preview for inventory, contextual matching, owner decisions and evidence-based verification. No system-specific result is generated by this page.

See the synthetic workflow preview ↗