{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-58054", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-06-28T00:55:25.426Z", "datePublished": "2026-06-28T01:32:56.492Z", "dateUpdated": "2026-06-28T01:32:56.492Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-06-28T01:32:56.492Z"}, "datePublic": "2026-06-23T00:00:00.000Z", "title": "MyBB - Privilege Escalation from Limited ACP User Management to Administrator", "descriptions": [{"lang": "en", "value": "MyBB 1.8.40 does not restrict which usergroup a limited Admin Control Panel user may assign when creating or editing users; the user module offers the Administrators group (gid 4) and its datahandler's verify_usergroup() unconditionally returns true. An admin holding only the delegated user-management permission can assign the Administrators group to an account and escalate to the full Administrator permission set."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improper Privilege Management", "cweId": "CWE-269", "type": "CWE"}]}], "affected": [{"vendor": "MyBB", "product": "MyBB", "defaultStatus": "affected", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThanOrEqual": "1.8.40"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*", "versionEndIncluding": "1.8.40"}]}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseScore": 7.2, "baseSeverity": "HIGH"}}, {"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.6, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/bikini/exploitarium/tree/main/mybb-limited-acp-to-admin", "name": "Proof of Concept", "tags": ["exploit", "third-party-advisory"]}, {"name": "VulnCheck Advisory: MyBB - Privilege Escalation from Limited ACP User Management to Administrator", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/mybb-privilege-escalation-from-limited-acp-user-management-to-administrator"}], "credits": [{"lang": "en", "value": "ashdfrkl", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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