CVE Catalog

CVE-2026-55158

CriticalCVSS 9.1
Published: Translated: NVD NIST

Summary

Conflibot prior to 1.2.1 builds git checkout, git merge, and git format-patch commands by interpolating the attacker-controlled pull request head.ref value into strings passed to exec. In the documented pull_request_target configuration, an attacker can open a pull request whose branch name contains shell metacharacters that are executed without maintainer interaction. The issue is fixed in versions 1.2.1 and 2.0.0.

Risk Assessment

Arbitrary command execution on a runner with base-repository secrets and a write-scoped GITHUB_TOKEN is possible, risking secret exfiltration, unauthorized pushes, and other token abuse. The risk is high in repositories using pull_request_target.

Recommendation

Upgrade Conflibot to version 1.2.1 or 2.0.0. Review pull_request_target workflow configurations and limit GITHUB_TOKEN permissions.

Related vulnerabilities

Original NVD description (English source)

Conflibot warns in advance when merging a pull request will cause conflicts in other open pull requests. Prior to 1.2.1, src/index.ts builds git checkout, git merge, and git format-patch commands by interpolating the attacker-controlled pull request head.ref value into strings passed to exec. In the documented pull_request_target configuration, an attacker can open a pull request, including from a fork, whose branch name contains shell metacharacters, and the workflow automatically interprets those characters as commands without maintainer interaction. The commands execute on a runner with base-repository secrets and a write-scoped GITHUB_TOKEN, allowing arbitrary command execution, secret or token exfiltration, unauthorized pushes, and other token abuse. The fixed implementations in src/index.ts and src/conflibot.ts use execFile or spawn argument arrays, and the v2 line also uses numeric pull-request refs rather than branch names. This issue is fixed in versions 1.2.1 and 2.0.0.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS