CVE Intelligence
Skip to main content
MEDIUM

CVE-2026-59944

CVE-2026-59944 — Composer: CVE-2026-59946 fix bypass via symlinked package bin path

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and from 2.3.0 until 2.10.3, a malicious or compromised dependency can bypass the earlier CVE-2026-59946 binary-path hardening because Composer validates literal parent-directory segments only during dependency resolution, while the symlink and installed-metadata paths described by the advisory skip that validation. A package can ship an in-package binary symlink that resolves outside its installation directory, or attacker-influenced vendor/composer/installed.json metadata can provide an escaping binary path during a reinstall or regeneration of missing vendor/bin entries. The installed-metadata path is reachable only when the vendor directory was not populated by the same validated install run, such as when it is restored from an untrusted cache, copied from an earlier build stage, carried over from an older…

Published Updated Sources: cvelistV5, GitHub_M

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

0%

chance of exploitation in 30 days

Affects

composer

composer

CVSS base

6.1

MEDIUM

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

No

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

composer

Products (1)

composer

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactSource
6.1CVSS 3.1MEDIUM——cvelistV5

Weakness & attack patterns

  • CWE-22
  • CWE-59

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

  • T1547.009Boot or Logon Autostart Execution: Shortcut Modification
  • T1574.005Hijack Execution Flow: Executable Installer File Permissions Weakness
  • T1574.010Hijack Execution Flow: Services File Permissions Weakness

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

  • Search application, proxy, and WAF logs for requests touching /composer/installed.json, /bin.

References

5 on the record

Elsewhere on this site

  • composerevery CVE for this vendor
  • CWE-22other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.