{"id":"CVE-2026-55158","title":"Conflibot warns in advance when merging a pull request will cause conflicts in other open pull requests","summary":"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 …","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-78"],"vendor":"wktk","product":"conflibot","affected":["conflibot < 1.2.1"],"patched":["wktk/conflibot 1.2.1"],"published":"2026-09-15","updated":"2026-09-17","sourceUpdated":"2026-09-17T15:16:48.047","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55158","references":[{"url":"https://github.com/wktk/conflibot/commit/0107ac6a4575ea200d0b92287ea58f975be9505d","label":"security-advisories@github.com"},{"url":"https://github.com/wktk/conflibot/commit/59e255c49c920fd6b67471ab9ef3bf194439a3f2","label":"security-advisories@github.com"},{"url":"https://github.com/wktk/conflibot/pull/329","label":"security-advisories@github.com"},{"url":"https://github.com/wktk/conflibot/releases/tag/v1.2.1","label":"security-advisories@github.com"},{"url":"https://github.com/wktk/conflibot/releases/tag/v2.0.0","label":"security-advisories@github.com"},{"url":"https://github.com/wktk/conflibot/security/advisories/GHSA-2qvg-qr73-mqxp","label":"security-advisories@github.com"},{"url":"https://github.com/wktk/conflibot/commit/0107ac6"},{"url":"https://github.com/wktk/conflibot/commit/59e255c"},{"url":"https://github.com/advisories/GHSA-2qvg-qr73-mqxp"}],"tags":["nvd","cve.org","ghsa","actions"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-09-17T14:42:13.306848Z"},"epss":0.00445,"epssPercentile":0.38078,"aliases":["GHSA-2qvg-qr73-mqxp"],"ecosystem":"actions","ingestedAt":"2026-08-17T13:54:47.924Z","slug":"CVE-2026-55158","body":"## Overview\n\nConflibot 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55158)\n\nAffected packages:\n\n- `wktk/conflibot < 1.2.1`\n\nPatched in:\n\n- `wktk/conflibot 1.2.1`\n\nSource: https://github.com/advisories/GHSA-2qvg-qr73-mqxp","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}