CVE-2023-27581

github-slug-action vulnerable to arbitrary code execution

HIGH
8.8
CVSS Score
Published: March 13, 2023 at 08:19 PM UTC
Updated: June 17, 2026 at 05:45 AM UTC
2 products affected across 2 vendorsGitHub Slug ActionSlug Action Project GitHub Slug Action

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Severity
HIGH8.8
Exploit prediction
EPSS 2%
SSVC
No known exploit

Description

github-slug-action is a GitHub Action to expose slug value of GitHub environment variables inside of one's GitHub workflow. Starting in version 4.0.0` and prior to version 4.4.1, this action uses the `github.head_ref` 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. This can be used to execute code on the GitHub runners and to exfiltrate any secrets one uses in the CI pipeline. A patched action is available in version 4.4.1. No workaround is available.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.0.0 ≤ v < 4.4.1
Affected range stops below 4.4.1, so it looks safe — our inference, not a vendor statement
v < 4.4.1
Affected range stops below 4.4.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-77

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