Protection Mechanism Failure vulnerability in hexpm hex allows the owner of a package, or an attacker who has taken over the owner's account, to get a newly published release past the release-age cooldown.

The cooldown (cooldown config, HEX_COOLDOWN) withholds versions younger than the configured age during dependency resolution. When the release of a package locked in mix.lock is retired or has a security advisory, Hex.RemoteConverger.build_cooldown_bypass/3 and Hex.RemoteConverger.unsafe_lock_bypass/1 lift the cooldown for every version of that package and of every package the locked release depends on, so that mix deps.update can move off the unsafe release. Retiring a release needs the same package owner permission as publishing one. An attacker who publishes a malicious release can retire the currently locked release, and the next mix deps.update that unlocks the package selects the new release regardless of its age. Hex.Registry.Cooldown.versions/2 checks the bypass by package name alone, so the bypass also covers packages with the same name in other repositories. Cooldown configured through an organization dependency policy is not affected.

This issue affects hex: from 2.5.0 before 2.5.2.
Advisories

No advisories yet.

Fixes

Solution

Upgrade Hex to 2.5.2 or later, for example with mix local.hex. A retired locked release then no longer lifts the release-age cooldown for its package. A locked release with a security advisory still lifts it for its package and the direct dependencies of the locked release, only in the repository the package is locked from.


Workaround

Enforce the cooldown through an organization dependency policy instead of the local cooldown setting, or run mix hex.audit before mix deps.update and don't update a package whose locked release was retired until its replacement has been reviewed.

History

Mon, 12 Oct 2026 15:45:00 +0000

Type Values Removed Values Added
Description Protection Mechanism Failure vulnerability in hexpm hex allows the owner of a package, or an attacker who has taken over the owner's account, to get a newly published release past the release-age cooldown. The cooldown (cooldown config, HEX_COOLDOWN) withholds versions younger than the configured age during dependency resolution. When the release of a package locked in mix.lock is retired or has a security advisory, Hex.RemoteConverger.build_cooldown_bypass/3 and Hex.RemoteConverger.unsafe_lock_bypass/1 lift the cooldown for every version of that package and of every package the locked release depends on, so that mix deps.update can move off the unsafe release. Retiring a release needs the same package owner permission as publishing one. An attacker who publishes a malicious release can retire the currently locked release, and the next mix deps.update that unlocks the package selects the new release regardless of its age. Hex.Registry.Cooldown.versions/2 checks the bypass by package name alone, so the bypass also covers packages with the same name in other repositories. Cooldown configured through an organization dependency policy is not affected. This issue affects hex: from 2.5.0 before 2.5.2.
Title Hex release-age cooldown is lifted package-wide when the locked release is retired
First Time appeared Hexpm
Hexpm hex
Weaknesses CWE-693
CPEs cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*
Vendors & Products Hexpm
Hexpm hex
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-10-12T15:31:58.926Z

Reserved: 2026-10-07T22:15:01.885Z

Link: CVE-2026-105668

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-12T16:17:02.943

Modified: 2026-10-12T16:17:02.943

Link: CVE-2026-105668

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-12T18:15:14Z

Weaknesses