CVE-2026-41082

High

Published: 16 April 2026

Published

16 April 2026

Modified

21 April 2026

KEV Added

—

Patch

—

CVSS Score v3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

EPSS Score 0.0001 0.5th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-41082 is a high-severity Path Traversal: '../filedir' (CWE-24) vulnerability. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Compromise Software Supply Chain (T1195.002); ranked at the 0.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-41082 is a path traversal vulnerability (CWE-24) in the OCaml opam package manager prior to version 2.5.1. The issue arises when processing a .install field in a package specification, which allows the destination filepath to include "../" sequences. This enables traversal to parent directories outside the intended installation scope. The vulnerability received a CVSS v3.1 base score of 7.3 (AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L), indicating high severity due to significant integrity impacts with low complexity and no privileges required.

A local attacker can exploit this vulnerability by creating or controlling a malicious opam package with a crafted .install field that uses "../" to target files in parent directories. Upon installation via opam, the package installs files to unauthorized locations, potentially overwriting critical system files. This grants high integrity disruption (I:H) with low confidentiality (C:L) and availability (A:L) impacts, all without user interaction or elevated privileges, as long as the victim runs the opam install command locally.

Mitigation involves updating to opam version 2.5.1 or later, as detailed in the official release notes and the corresponding GitHub pull request #6897 that addresses the path traversal. Debian LTS users should refer to the security announcement for patched packages in their repositories. No workarounds are specified beyond avoiding installation of untrusted packages.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-23288

Vulnerability details

In OCaml opam before 2.5.1, a .install field containing a destination filepath can use ../ to reach a parent directory.

CWE(s): CWE-24

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1195.002 Compromise Software Supply Chain Initial Access

Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.

attack.mitre.org →

T1204.002 Malicious File Execution

An adversary may rely upon a user opening a malicious file in order to gain execution.

attack.mitre.org →

Why these techniques?

The path traversal vulnerability in opam enables a malicious package with crafted .install field to write files to arbitrary locations outside intended scope, directly facilitating supply chain compromise through the package and requiring user execution of the opam install command on the malicious package file.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1