What’s Vulnerable › Vulnerabilities

CVE-2026-34042: act: actions/cache server allows malicious cache injection

• Severity: high (CVSS 8.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-31 · updated 2026-06-17
• Weakness: CWE-862

Description

act is a project which allows for local running of github actions. Prior to version 0.2.86, act's built in actions/cache server listens to connections on all interfaces and allows anyone who can connect to it including someone anywhere on the internet to create caches with arbitrary keys and retrieve all existing caches. If they can predict which cache keys will be used by local actions, they can create malicious caches containing whatever files they please most likely allowing arbitrary remote code execution within the docker container. This issue has been patched in version 0.2.86.

Affected products

• nektos act: before 0.2.86

References

• https://code.forgejo.org/forgejo/runner/issues/294
• https://github.com/nektos/act/commit/c28c27e141e8b54f9853de82f421ee09846751f7
• https://github.com/nektos/act/releases/tag/v0.2.86
• https://github.com/nektos/act/security/advisories/GHSA-x34h-54cw-9825

Get alerted when CVE-2026-34042 or the next vulnerability affects your stack