8.2

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

Deferred
AliasesGHSA-x34h-54cw-9825GO-2026-4890
Published 31-03-2026Last modified 31-03-2026

Vulnerability summary

CVE-2026-34042 is a high (CVSS 8.2) Missing Authorization vulnerability in nektos act. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 40.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 8.2, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.2/10
010
High · v3.1 (CVE.org)
EPSS score
0.47%
0%100%
Low · -0.11 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:21483-1SUSE-SU-2026:1205-1

Timeline

  1. 31-03-2026
    PublishedVulnerability first disclosed.
  2. 31-03-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.47%

Chance of exploitation in the next 30 days

Percentile

41%

Versus all other CVEs

30-day change

Decrease -0.11 pp

From 0.58% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Github.com/nektos1 product
  • act< 0.2.86
Nektos1 product

2 vendors · 2 products

References

6 links