CVE-2026-59948

Composer: Arbitrary file write outside vendor via malicious transitive package name

HIGH
7
CVSS Score
Published: July 8, 2026 at 07:33 PM UTC
Updated: July 10, 2026 at 07:28 PM UTC
1 product affected across 1 vendorComposer

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Severity
HIGH7
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

Composer is a dependency Manager for the PHP language. Prior to 2.2.29 and 2.10.2, a maliciously crafted package from an untrusted repository other than Packagist.org or Private Packagist can cause Composer to write attacker-controlled files outside the vendor directory and outside the project during install or update by using an invalid package name that is not correctly validated before dependency-resolution results are written or installed. This issue is fixed in versions 2.2.29 and 2.10.2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.10.2v < 2.2.29
Affected range stops below 2.10.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.2.29, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7HIGHGitHub_M
Attack Vector
LOCAL
Complexity
HIGH
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-22CWE-787

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