Out-of-scope file write via unchecked install destination
Published Apr 16, 2026 · Updated Apr 16, 2026
Path traversal in OCaml opam before 2.5.1 allows attackers to write files outside the package area through a crafted .install destination. Dot_installSyntax treated the destination as a relative filename without rejecting parent-directory segments, so opam resolved ../ outside its intended install scope. Processing an attacker-controlled package is required, and the write runs with the privileges of the opam process.
Summary
What happened
Path traversal in OCaml opam before 2.5.1 allows attackers to write files outside the package area through a crafted .install destination. Dot_installSyntax treated the destination as a relative filename without rejecting parent-directory segments, so opam resolved ../ outside its intended install scope. Processing an attacker-controlled package is required, and the write runs with the privileges of the opam process.
The record
- CVE
- CVE-2026-41082
- Published
- Apr 16, 2026
- Updated
- Apr 16, 2026
- Vendor
- OCaml
- Product
- opam
- Classifications
- CWE-693, CWE-24, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 16, 2026CVE publishedPublication date reported by the CVE source.
- Apr 16, 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=0 <2.5.1
What conditions does exploitation require?
What is affected?
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
- Crafted .install parent-directory destination exampleproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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