Cyber Resilience

CVE-2026-41082

Path Traversal in Ocaml Opam ≤ 2.5.1

Published
16 April 2026
Modified
15 July 2026
Patch / advisory
CVSS Score v3.1 7.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
EPSS Score 0.0021 11th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

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

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 11th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-5115Same product: Debian Debian Linux
CVE-2024-8409Shared CWE-22, CWE-24
CVE-2023-20166Shared CWE-22, CWE-24
CVE-2025-43928Shared CWE-22, CWE-24
CVE-2024-0354Shared CWE-22, CWE-24
CVE-2024-3686Shared CWE-22, CWE-24
CVE-2026-28427Shared CWE-22, CWE-24
CVE-2024-37403Shared CWE-22, CWE-24
CVE-2024-6786Shared CWE-22, CWE-24
CVE-2023-1398Shared CWE-22, CWE-24

Affected Assets

ocaml
opam
≤ 2.5.1
debian
debian linux
11.0
redhat
enterprise linux
10.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

Enforces the intended directory access authorizations that path traversal would otherwise bypass.

Input validation directly neutralizes '../' sequences in externally-supplied pathnames before they are resolved.

Least privilege reduces the impact of any unauthorized file access obtained via traversal.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and path sanitization that prevent ../ traversal.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding standards require neutralizing ../ sequences and canonicalizing paths before file operations.

finds

Security testing in development catches path-traversal flaws before release.

prevents

Secure SDLC mandates input validation and path canonicalization that directly block ../ traversal.

prevents

Application security requirements explicitly call for controls against path traversal in file-handling functions.

prevents

Secure architecture principles reduce attack surface but do not prescribe the specific coding fix.

mitigates

Information access restriction limits which files can be reached, mitigating impact of traversal.

References