MyBB is free and open source forum software. Prior to 1.8.40, the Mod CP Report Center does not check permissions consistently, allowing moderators without report-management permission to mark reports as resolved. The modcp.php?action=do_reports Mark Selected as Read handler is reachable with canmodcp even without canmanagereportedcontent or canmanagereportedposts. When no forums are in scope, $flist_reports is empty and the UPDATE mybb_reportedcontent query executes without the expected permission-based limitation. This issue is fixed in version 1.8.40.
https://mybb.com/versions/1.8.40
https://github.com/mybb/mybb/security/advisories/GHSA-gfxj-g7w6-6w4v
https://github.com/mybb/mybb/releases/tag/mybb_1840
https://github.com/mybb/mybb/commit/5cda5f6d183bc2cac24f0533e8d3060a9a46cc42