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=recoverycodes page regenerates Two-Factor Authentication recovery codes in mybbadminoptions.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.
{
"unresolved_ranges": [
{
"extracted_events": [
{
"fixed": "1.8.40"
}
],
"source": "AFFECTED_FIELD"
}
],
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-352"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45129.json"
}