Sandbox escape via unresolved symlink destinations
Published Sep 9, 2026 · Updated Sep 9, 2026
Sandbox escape in OCaml opam before 2.5.2 allows remote authenticated users to write files outside the active switch. In preprocess_dot_install_t, the installer checks the declared destination against the switch but installs through unresolved symlink components. Exploitation requires a user to install an attacker-controlled package whose build creates the link; resulting writes carry the installing user's filesystem permissions.
Summary
What happened
Sandbox escape in OCaml opam before 2.5.2 allows remote authenticated users to write files outside the active switch. In preprocess_dot_install_t, the installer checks the declared destination against the switch but installs through unresolved symlink components. Exploitation requires a user to install an attacker-controlled package whose build creates the link; resulting writes carry the installing user's filesystem permissions.
The record
- CVE
- CVE-2026-57825
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- OCaml
- Product
- opam
- Classifications
- CWE-61, CWE-693, T1204.002
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 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 <2.5.2
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
- OSEC-2026-10 malicious package exampleproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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