Privilege escalation in Step-Security Harden-Runner

CVE-2025-32955

Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. Versions from 0.12.0 to before 2.12.0 are vulnerable to `disable-sudo` bypass. Harden-Runner includes a policy option `disable-sudo` to prevent the GitHub Actions runner user from using sudo. This is implemented by removing the runner user from the sudoers file. However, this control can be bypassed as the runner user, being part of the docker group, can interact with the Docker daemon to launch privileged containers or access the host filesystem. This allows the attacker to regain root access or restore the sudoers file, effectively bypassing the restriction. This issue has been patched in version 2.12.0.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (12.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-32955: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-32955?
CVE-2025-32955 is a medium-severity vulnerability in Step-Security Harden-Runner, classified under Privilege Chaining. CVSS score: 6.0/10. Published 2025-04-21.
How severe is CVE-2025-32955?
Medium severity. CVSS v3 base score is 6.0 out of 10.