Sensitive file exposure via bin path traversal
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 expose host files during installs. The BinaryInstaller resolves each dependency's bin entry relative to its package directory without rejecting .. segments, then applies chmod to the resolved path with world-readable and world-executable permissions. Exploitation requires installation or update of an untrusted direct or transitive dependency and an existing writable target file; the flaw changes permissions but does not read, alter, or execute file contents.
Summary
What happened
Path traversal in Composer 1.0 through 2.2.28 and 2.3.0 through 2.10.1 allows attackers to expose host files during installs. The BinaryInstaller resolves each dependency's bin entry relative to its package directory without rejecting .. segments, then applies chmod to the resolved path with world-readable and world-executable permissions. Exploitation requires installation or update of an untrusted direct or transitive dependency and an existing writable target file; the flaw changes permissions but does not read, alter, or execute file contents.
The record
- CVE
- CVE-2026-59946
- Published
- Jul 8, 2026
- Updated
- Jul 8, 2026
- Vendor
- Composer
- Product
- Composer
- Classifications
- CWE-22, CWE-732, T1222.002
- 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
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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.
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Technologies
Your stack
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Your stack
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