# CVE-2026-34042: GO-2026-4890 - act: actions/cache server allows malicious cache injection in github.com/nektos/act

Source: https://junglewise.ai/threats/cve-2026-34042-act-actions-cache-server-allows-malicious-cache-injection  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-02  
License: CC BY 4.0 with a link back

CVE-2026-34042 · Severity: low · CVSS 3.1 · Published 2026-04-02

act: actions/cache server allows malicious cache injection in github.com/nektos/act

Technologies: [github.com/nektos/act (Go)](https://junglewise.ai/threats/technologies/github-com-nektos-act). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-34042 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34042 being exploited in the wild.

**How severe is CVE-2026-34042?** Low severity, with a CVSS score of 3.1, published 2 April 2026.

**Which products and versions are affected?** github.com/nektos/act (Go) SEMVER:introduced=0,fixed=0.2.86.

**Is there a fix for CVE-2026-34042?** Yes. github.com/nektos/act (Go): upgrade to 0.2.86 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-34042?** Check whether you run github.com/nektos/act (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/nektos/act (Go): upgrade to 0.2.86 or later

  ```sh
  go get github.com/nektos/act@v0.2.86
  ```


## Affected products

- github.com/nektos/act (Go) SEMVER:introduced=0,fixed=0.2.86

## Identifiers

- CVE-2026-34042
- GHSA-x34h-54cw-9825
- GO-2026-4890

## Related threats

- [GO-2026-4891 - act: Unrestricted set-env and add-path command processing enables environment injection in github.com/nektos/act](https://junglewise.ai/threats/cve-2026-34041-act-unrestricted-set-env-and-add-path-command-processing-enables)
- [GO-2023-1504 - act vulnerable to arbitrary file upload in artifact server in github.com/nektos/act](https://junglewise.ai/threats/cve-2023-22726-act-vulnerable-to-arbitrary-file-upload-in-artifact-server)