CVE-2026-45129 PUBLISHED

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Recovery Codes module does not validate requests correctly, allowing same-site attackers to rotate a victim administrator's recovery codes with a specially crafted URL. The Admin CP Home, Preferences, Recovery Codes action=recovery_codes page regenerates Two-Factor Authentication recovery codes in mybb_adminoptions.recovery_codes on GET requests without request forgery protection. The uniquely identifying implementation details include admin/modules/home/preferences.php. This issue is fixed in version 1.8.40.

• https://github.com/mybb/mybb/security/advisories/GHSA-75vg-6wgp-mcc9
• https://github.com/mybb/mybb/commit/d2d9e47b53d85101cf25cb47e882bc7ba76355a4
• https://github.com/mybb/mybb/releases/tag/mybb_1840
• https://mybb.com/versions/1.8.40

• CWE-352: Cross-Site Request Forgery (CSRF) CWE