CVE-2026-105668 Hex release-age cooldown is lifted package-wide when the locked release is retired

What is CVE-2026-105668?

CVE-2026-105668 is a high-severity vulnerability in hexpm hex, published on 12 Oct 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official 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.

Weakness: CWE-693

Which versions are affected by CVE-2026-105668?

How do I fix CVE-2026-105668?

Upgrade to a fixed version.

Is CVE-2026-105668 being exploited?

There is no known exploitation of CVE-2026-105668 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-105668, EEF-CVE-2026-105668, GHSA-pqhp-5x9x-69h7, UBUNTU-CVE-2026-105668.