CVE-2026-23939: hex hexpm Path Traversal

Vulnerability summary

CVE-2026-23939 is a high (CVSS 7.5) Path Traversal vulnerability in hex hexpm. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.3% of scored vulnerabilities.

Timeline

1. 26-02-2026
   PublishedVulnerability first disclosed.
2. 16-09-2026
   Last modifiedVulnerability information updated.

Description

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in hexpm hexpm/hexpm ('Elixir.Hexpm.Store.Local' module) allows Relative Path Traversal. This vulnerability is associated with program files lib/hexpm/store/local.ex and program routines 'Elixir.Hexpm.Store.Local':get/3, 'Elixir.Hexpm.Store.Local':put/4, 'Elixir.Hexpm.Store.Local':delete/2, 'Elixir.Hexpm.Store.Local':delete_many/2. This issue does NOT affect hex.pm the service. Only self-hosted deployments using the Local Storage backend are affected. This issue affects hexpm: from 931ee0ed46fa89218e0400a4f6e6d15f96406050 before 5d2ccd2f14f45a63225a73fb5b1c937baf36fdc0.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.