Critical, CVSS 9.1GitHub ActionsAmendedPublished
conflibot vulnerable to command injection via crafted pull request branch names under pull_request_target
CVE-2026-55158 · GHSA-2qvg-qr73-mqxp
- Affected
- GitHub Actions wktk/conflibot < 1.2.1
- Fixed in
- 1.2.1· Vendor fix available
- Issue
- Impact Versions of conflibot before 1.2.1 build git commands by string interpolation and run them through a shell. Several of the interpolated values are pull request branch names (head.ref), which are attacker-controlled: anyone can open a pull request (including from a fork) whose head branch name contains shell metacharacters such as , $( ), ;, |, or &. The recommended workflow runs conflibot on the pullrequesttarget event, where the job has access to the base repository's secrets and a write-scoped GITHUBTOKEN. As a result, a crafted branch name causes arbitrary command execution on the runner with that write token in the environment, allowing an attacker to exfiltrate secrets and the token, push to the repository, or otherwise abuse the token's permissions. No special privileges and no maintainer interaction are required — the action runs automatically when the pull request is opened. Affected configurations Any workflow using wktk/conflibot at a version earlier than 1.2.1. The…
Recommended action: Upgrade to 1.2.1 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.