Arbitrary file write via unvalidated package names
Published Jul 8, 2026 · Updated Jul 8, 2026
Path traversal in Composer 1.0 through 2.2.28 and 2.3.0 through 2.10.1 allows attackers to write files outside a project. LockTransaction::setResultPackages accepts dependency-solver packages loaded through nonvalidating ArrayLoader paths and writes or installs them without rechecking vendor/package names. Exploitation requires an install or update that resolves a malicious or compromised package from an untrusted third-party repository; crafted names can place startup, SSH authorization, or cron files under the Composer process account.
Summary
What happened
Path traversal in Composer 1.0 through 2.2.28 and 2.3.0 through 2.10.1 allows attackers to write files outside a project. LockTransaction::setResultPackages accepts dependency-solver packages loaded through nonvalidating ArrayLoader paths and writes or installs them without rechecking vendor/package names. Exploitation requires an install or update that resolves a malicious or compromised package from an untrusted third-party repository; crafted names can place startup, SSH authorization, or cron files under the Composer process account.
The record
- CVE
- CVE-2026-59948
- Published
- Jul 8, 2026
- Updated
- Jul 8, 2026
- Vendor
- Composer
- Product
- Composer
- Classifications
- CWE-22, CWE-787, T1195.001
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 8, 2026CVE publishedPublication date reported by the CVE source.
- Jul 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 1.0, < 2.2.29
- Affected versionversion=>= 2.3.0, < 2.10.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo