{"id":"CVE-2026-118762","published":"2026-10-29T17:18:07.070","lastModified":"2026-10-29T17:18:07.200","description":"Monkeytype is a minimalistic and customizable typing test. Prior to 26.43.0, the .github/workflows/fix-formatting.yml workflow runs on pull_request_target with repository write permissions, checks out a fork pull request, installs dependencies from the fork's package.json, and invokes the fork-controlled oxfmt binary. Because actions/checkout persists the elevated GITHUB_TOKEN in Git configuration until after untrusted code executes, an external contributor whose pull request receives the format label can run arbitrary code, read or exfiltrate the token, and push repository content or modify pull requests and issues. The issue affects the repository CI workflow, not the Monkeytype application or user data. This issue is fixed in version 26.43.0.","cvssScore":9.3,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N","cwes":["CWE-829"],"vendors":[],"products":[],"references":[{"url":"https://github.com/monkeytypegame/monkeytype/commit/592ce1becb9b6824badc14a803bcd9268cbea382","tags":[]},{"url":"https://github.com/monkeytypegame/monkeytype/releases/tag/v26.43.0","tags":[]},{"url":"https://github.com/monkeytypegame/monkeytype/security/advisories/GHSA-47v3-j88w-92f8","tags":[]}],"exploitRefs":[{"url":"https://github.com/monkeytypegame/monkeytype/commit/592ce1becb9b6824badc14a803bcd9268cbea382","tags":[]},{"url":"https://github.com/monkeytypegame/monkeytype/releases/tag/v26.43.0","tags":[]},{"url":"https://github.com/monkeytypegame/monkeytype/security/advisories/GHSA-47v3-j88w-92f8","tags":[]}],"hasPoc":true,"ai":{"summary":"The GitHub Actions workflow .github/workflows/fix-formatting.yml in Monkeytype prior to v26.43.0 executes untrusted forked code with elevated repository write permissions due to improper handling of the GITHUB_TOKEN, allowing an attacker to run arbitrary code and exfiltrate credentials.","exploitability":"Exploitation requires an external contributor to submit a pull request that receives the 'format' label, triggering the vulnerable workflow with repository write access.","blast_radius":"Successful exploitation allows the attacker to push malicious commits, modify issues or pull requests, and potentially compromise repository integrity and CI/CD supply chain trust.","remediation":"Upgrade Monkeytype to version 26.43.0 or later, which fixes the workflow to avoid persisting the elevated GITHUB_TOKEN before untrusted code execution.","detection":"Monitor GitHub Actions workflow runs for unexpected execution of fork-provided binaries (e.g., oxfmt) in workflows triggered by pull_request_target with repository write permissions; look for anomalous Git pushes or token usage in workflow logs.","tags":["ci-cd-compromise","token-exfiltration","supply-chain","rce"],"model":"garnet-coder","analyzedAt":"2026-10-30T09:18:56.443Z"}}