CVE-2026-34042 HIGH

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

Vendor Nektos
Product act
Weakness CWE-862 · Missing authorization
Published March 31, 2026
Last update March 31, 2026

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality High
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 31, 2026 CVE published
March 31, 2026 Record updated