Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34042act: actions/cache server allows malicious cache injection
High 8.2
In plain English
A high-severity missing authorization in act from nektos. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/nektos/act | 0.2.86 | GHSA-x34h-54cw-9825 |
| Go | github.com/nektos/act | 0.2.86 | GO-2026-4890 |
Affected products (as reported)
Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
References
- https://github.com/nektos/act/security/advisories/GHSA-x34h-54cw-9825 x_refsource_CONFIRM
- https://github.com/nektos/act/commit/c28c27e141e8b54f9853de82f421ee09846751f7 x_refsource_MISC
- https://code.forgejo.org/forgejo/runner/issues/294 x_refsource_MISC
- https://github.com/nektos/act/releases/tag/v0.2.86 x_refsource_MISC