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Fencer Vulns
high 7.7

CVE-2026-84361 json

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

published 2026-09-01 2 mo ago modified 2026-09-10 1 mo ago also BIT-composer-2026-84361 , EUVD-2026-69608 , GHSA-rvx4-ffvw-m9q3

cvss
7.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

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.

Patch / fix

  • packagist composer/composer 2.2.30, 2.10.3
  • bitnami composer 2.2.30, 2.10.3
  • getcomposer composer 2.2.30, 2.10.3
  • composer Debian 14 2.10.3-1

debian advisories DEBIAN-CVE-2026-84361

  • composer hummingbird 1 2.10.3-1.hum1

red hat advisories RHSA-2026:63151

  • php-composer2 SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 2.2.30-150400.3.21.1
  • php-composer2 SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Web and Scripting 15 SP7 2.6.4-150600.3.18.1
  • php-composer2 SLES for SAP applications 16.0, SLES 16.0 2.8.9-160000.5.1

suse advisories SUSE-SU-2026:4283-1SUSE-SU-2026:4059-1SUSE-SU-2026:23635-1

  • php-composer2 openSUSE Leap 16.0 2.8.9-160000.5.1
  • php-composer2 openSUSE Tumbleweed 2.10.3-2.1

opensuse advisories openSUSE-SU-2026:21778-1openSUSE-SU-2026:11689-1

  • composer Alpine 3.24 2.10.3-r0

alpine advisories ALPINE-CVE-2026-84361

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-84361 updated cvss 7.3

composer: Composer: Arbitrary code execution via malicious Perforce source URL

  • Red Hat Hardened Images composer 2.10.3-1.hum1
    fixed: vendor fix RHSA-2026:63151

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.7 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.7 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
packagist composer/composer
>=2.3.0, <2.10.3
>=1.0, <2.2.30
2.10.3
2.2.30
bitnami composer
>=1.0.0, <2.2.30
>=2.3.0, <2.10.3
2.2.30
2.10.3

Affected products

  • composer composer

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.