CSRF in Mybb
CVE-2026-45129
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.
Vulnerability class: CSRF (Cross-Site Request Forgery)
CVSS v3 metric
CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L.
Affected products
- Mybb — versions < 1.8.40
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-45129?
- CVE-2026-45129 is a medium-severity vulnerability in Mybb, classified under Cross-Site Request Forgery (CSRF). CVSS score: 4.6/10. Published 2026-08-18.
- How severe is CVE-2026-45129?
- Medium severity. CVSS v3 base score is 4.6 out of 10.