github-slug-action vulnerable to arbitrary code execution

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.8 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2023-27581: 1.58% estimated exploitation activity in the next 30 days; percentile 75.49 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact This action uses the github.headref parameter in an insecure way. This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. (Note that first-time PR requests will not be run - but the attacker can submit a valid PR before submitting an invalid PR). This can be used to execute code on the GitHub runners (potentially use it for crypto-mining, and waste your resources) and to exfiltrate any secrets you use in the CI pipeline. Patches Pass the variable as an environment variable and then use the environment variable instead of substituting it directly. Patched action is available on tag v4, tag v4.4.1, and any tag beyond. Workarounds No workaround is available if impacted, please upgrade the version ℹ️ v3 and v4 are compatibles. References Here is a set of blog posts by Github's security team explaining this issue. Thanks Thanks to…

Published by the source

13 Mar 2023, 20:43 UTC

Last modified by the source

18 Feb 2025, 22:42 UTC

Source last checked

26 Oct 2026, 17:08 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6q4m-7476-932w

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# Patch Next advisory brief: CVE-2023-27581

Advisory: github-slug-action vulnerable to arbitrary code execution
IDs: CVE-2023-27581, GHSA-6q4m-7476-932w
Record: https://patchnext.com/advisories/cve-2023-27581 (revision 1, source checked 26 Oct 2026, 17:08 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: rlespinasse/github-slug-action 4.4.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- GitHub Actions rlespinasse/github-slug-action: affected >= 4.0.0, < 4.4.1; fixed in 4.4.1

## Suggested inspection (read-only)
- GitHub Actions rlespinasse/github-slug-action: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on rlespinasse/github-slug-action.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6q4m-7476-932w (GitHub-reviewed advisory GHSA-6q4m-7476-932w lists affected ranges: GitHub Actions rlespinasse/github-slug-action >=4.0.0 <4.4.1)

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