CVE-2026-96612: Path traversal in Hex via unvalidated dependency app names

Severity: high (CVSS 7.5 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-12 · updated 2026-10-16
Weakness: CWE-22

Description

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in hexpm hex allows a malicious package publisher to delete a directory outside the project's deps directory and extract package files into it when a developer fetches dependencies. A package release's requirements carry an app label that names the dependency's OTP application. Hex takes this label from the repository's signed registry and uses it as the dependency's application name without validating it (Hex.RemoteConverger.deps/2, Hex.Mix.to_lock/1). Mix derives the dependency's checkout directory as deps/<app>, and Hex.SCM.update/1 runs File.rm_rf!/1 on that directory and unpacks the package into it. hex.pm only checks the label's length, so a publisher can set it to a value such as ../../target. When a project depends on such a release directly or transitively, mix deps.get or mix deps.update deletes the directory the label resolves to and writes the labelled package's files there. This happens before any dependency code is compiled. This issue affects hex: from 0.6.0 before 2.5.2.

Affected products

hexpm hex: from 0.6.0 before 2.5.2 — fixed in 2.5.2

How to fix

Upgrade to a fixed version: hexpm hex 2.5.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-96612 or the next vulnerability affects your stack