{"cve":{"cve_id":"CVE-2026-58054","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":null,"epss_percentile":null,"epss_as_of":null,"description":"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.","published_at":"2026-06-28T01:32:56.492000Z","last_modified_at":null,"cvss_v3_score":7.2,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":8.6,"cvss_v4_vector":"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","cvss_v4_severity":"HIGH","ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-269"],"nvd_references":["https://github.com/bikini/exploitarium/tree/main/mybb-limited-acp-to-admin","https://www.vulncheck.com/advisories/mybb-privilege-escalation-from-limited-acp-user-management-to-administrator"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-28T17:55:42.709123Z","updated_at":"2026-06-28T23:30:59.112346Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"H","value_label":"High"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"N","value_label":"None"},{"metric":"PR","name":"Privileges Required","value":"H","value_label":"High"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"H","value_label":"High"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"H","value_label":"High"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"H","value_label":"High"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"N","value_label":"None"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"N","value_label":"None"},{"metric":"SA","name":"Availability (Subsequent System)","value":"N","value_label":"None"}]},"affected":[{"vendor_slug":"mybb","vendor_name":"MyBB","product_slug":"mybb","product_name":"MyBB","version_start":"0","version_start_inclusive":true,"version_end":"1.8.40","version_end_inclusive":true,"cpe23_uri":"cve5:mybb:mybb:0:1.8.40"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/bikini/exploitarium/tree/main/mybb-limited-acp-to-admin","source_type":"MISC","tags":[]},{"url":"https://www.vulncheck.com/advisories/mybb-privilege-escalation-from-limited-acp-user-management-to-administrator","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-06-28T01:32:56.492000Z","label":"CVE published","source":null}]}