CVE-2023-27581Network attack vector

Runner code execution via interpolated branch name

Published Mar 13, 2023 · Updated Feb 25, 2025

Command injection in rlespinasse GitHub Slug Action 4.0.0 through 4.4.0 allows remote authenticated users to execute code on runners. The get-github-ref-name step in action.yml directly interpolates github.head_ref into a double-quoted Bash assignment, causing shell substitutions in a branch name to execute. A GitHub user whose pull request runs in a workflow using an affected ref can execute commands in the runner context and read secrets exposed to that run.

CVSS severity8.8
High
EPSS probability1.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Command injection in rlespinasse GitHub Slug Action 4.0.0 through 4.4.0 allows remote authenticated users to execute code on runners. The get-github-ref-name step in action.yml directly interpolates github.head_ref into a double-quoted Bash assignment, causing shell substitutions in a branch name to execute. A GitHub user whose pull request runs in a workflow using an affected ref can execute commands in the runner context and read secrets exposed to that run.

The record

CVE
CVE-2023-27581
Published
Mar 13, 2023
Updated
Feb 25, 2025
Vendor
rlespinasse
Product
GitHub Slug Action
Classifications
CWE-77, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.0.0, < 4.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

rlespinasse · GitHub Slug Actionversion=>= 4.0.0, < 4.4.1

Published CVSS scores

8.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo