CVE-2026-23939 Path Traversal in Local File Store Backend

Medium 6.9 Published 26 Feb 2026 Updated 16 Sep 2026

Path traversal in hexpm's local storage backend allows attackers to read or modify files outside the intended directory in self-hosted deployments.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-23939?

CVE-2026-23939 is a medium-severity path traversal vulnerability in hexpm, published on 26 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-22

Which versions are affected by CVE-2026-23939?

It affects 1 product.

Products include Hex Hexpm.

How do I fix CVE-2026-23939?

No fix has been published for CVE-2026-23939 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-23939 being exploited?

There is no known exploitation of CVE-2026-23939 in the wild and no public exploit code.

Sources

Also known as EEF-CVE-2026-23939, GHSA-42mv-r64p-4869.