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

> Attackers can bypass release-age cooldowns in Hex by retiring locked releases, allowing malicious packages to be installed via dependency updates.

- **Severity:** High 7.1 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 12 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-105668, EEF-CVE-2026-105668, GHSA-pqhp-5x9x-69h7, UBUNTU-CVE-2026-105668

## 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 (Protection Mechanism Failure)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-105668 and fix it if it is affected.

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

Affected product: hexpm hex. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-105668/ (Markdown: https://insights.sbomify.com/CVE-2026-105668/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-105668
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-105668
- OSV: https://osv.dev/vulnerability/CVE-2026-105668

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-105668/
Summaries are generated and may contain mistakes; the official description above is the record.