CVE-2025-32955: Security mechanism bypass in Harden-Runner Github Action

CVE-2025-32955: Security mechanism bypass in Harden-Runner Github Action

The Sysdig Threat Research Team (TRT) has identified CVE-2025-32955, a significant vulnerability in the Harder-Runner GitHub Action that allows attackers to bypass the disable-sudo security feature, compromising CI/CD workflows. Users are encouraged to update to version v2.12.0 to mitigate this risk. Affected: GitHub Actions, CI/CD Tools

Keypoints :

  • Identified vulnerability: CVE-2025-32955 in Harden-Runner GitHub Action.
  • Exploitation allows bypassing of the disable-sudo security mechanism.
  • Vulnerability has a CVSS v3.1 base score of 6.0.
  • Harden-Runner aims to secure GitHub Action workflows by hardening job environments.
  • Attacker can gain sudo access and modify configurations undetected in the CI/CD pipeline.
  • Version v2.12.0 released to remediate the vulnerability on April 21, 2025.

MITRE Techniques :

  • Privilege Escalation (T1068) – Bypassing the disable-sudo feature to obtain root access using Docker.
  • Exploitation for Client Execution (T1203) – Executing commands within Docker containers to restore sudo privileges.

Indicator of Compromise :

  • [Domain] step-security/harden-runner
  • [Version] v2.12.0

Full Story: https://sysdig.com/blog/security-mechanism-bypass-in-harden-runner-github-action/