CVE-2026-45119 MyBB: ACP UTF-8 Conversion CSRF

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP UTF-8 Conversion module does not validate certain requests correctly, allowing same-site attackers to alter table encoding and deny service with a specially crafted URL. The do=all control flow in...

CVE-2026-45126 MyBB: ACP Questions state CSRF

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Security Questions module does not validate the anti-CSRF token correctly, allowing same-site attackers to enable or disable registration challenge questions with a specially crafted URL. The controller processes GET...

CVE-2026-45126

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Security Questions module does not validate the anti-CSRF token correctly, allowing same-site attackers to enable or disable registration challenge questions with a specially crafted URL. The controller processes GET...

CVE-2026-45126

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Security Questions module does not validate the anti-CSRF token correctly, allowing same-site attackers to enable or disable registration challenge questions with a specially crafted URL. The controller processes GET...

EUVD-2026-61007

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Security Questions module does not validate the anti-CSRF token correctly, allowing same-site attackers to enable or disable registration challenge questions with a specially crafted URL. The controller processes GET...

EUVD-2026-61006

MyBB is free and open source forum software. Prior to 1.8.40, the user datahandler does not properly validate checkbox and multiselect profile field types, resulting in stored JavaScript code injection. UserDataHandler::verifyprofilefields only performs the specialized validation when...

CVE-2026-45116 MyBB: Profile field type confusion XSS

MyBB is free and open source forum software. Prior to 1.8.40, the user datahandler does not properly validate checkbox and multiselect profile field types, resulting in stored JavaScript code injection. UserDataHandler::verifyprofilefields only performs the specialized validation when...

CVE-2026-45116

MyBB versions prior to 1.8.40 have a type-confusion flaw in UserDataHandler::verify_profile_fields() (inc/datahandlers/user.php): when a checkbox/multiselect profile field is submitted as a non-array value, the is_array() check is skipped, bypassing specialized validation. The unchecked value is ...

CVE-2026-45116

MyBB is free and open source forum software. Prior to 1.8.40, the user datahandler does not properly validate checkbox and multiselect profile field types, resulting in stored JavaScript code injection. UserDataHandler::verifyprofilefields only performs the specialized validation when...

CVE-2026-45115

MyBB's Buddy/Ignore component fails to escape single quotes in usernames via htmlspecialchars_uni(), enabling stored XSS in the User CP and Private Messages Select Buddies list. Victims are affected when confirming buddy removal in usercp.php or selecting buddies in the xmlhttp.php onclick handle...

EUVD-2026-61005

MyBB is free and open source forum software. Prior to 1.8.40, the Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messag...

CVE-2026-45115

MyBB is free and open source forum software. Prior to 1.8.40, the Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messag...

CVE-2026-45115 MyBB: Buddy/ignore list username XSS

MyBB is free and open source forum software. Prior to 1.8.40, the Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messag...

CVE-2026-45121

MyBB is free and open source forum software. Prior to 1.8.40, the calendar module does not check permissions consistently when listing calendars, allowing authenticated users to access titles of calendars that are otherwise inaccessible. The affected calendar-selection paths in calendar.php perfo...

CVE-2026-45121 MyBB: Insufficient permission check for calendar select

MyBB is free and open source forum software. Prior to 1.8.40, the calendar module does not check permissions consistently when listing calendars, allowing authenticated users to access titles of calendars that are otherwise inaccessible. The affected calendar-selection paths in calendar.php perfo...

EUVD-2026-61053

MyBB is free and open source forum software. Prior to 1.8.40, the calendar module does not check permissions consistently when listing calendars, allowing authenticated users to access titles of calendars that are otherwise inaccessible. The affected calendar-selection paths in calendar.php perfo...

CVE-2026-45121

In MyBB versions before 1.8.40, calendar.php performs permission checks against an invalid calendar context, allowing authenticated users to view titles of otherwise inaccessible calendars. CVSS 3.1 scores this MEDIUM (4.3) with network attack vector and low privileges required. Upgrade to versio...

EUVD-2026-61052

Impact The registration component does not validate the text-based Security Question CAPTCHA correctly, allowing attackers to bypass the challenge via a specially crafted value. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Details The public Registration workflow member.php?action=doregister...

CVE-2026-46482

Impact The registration component does not validate the text-based Security Question CAPTCHA correctly, allowing attackers to bypass the challenge via a specially crafted value. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Details The public Registration workflow member.php?action=doregister...

CVE-2026-46482 MyBB: Security Question insufficient validation

Impact The registration component does not validate the text-based Security Question CAPTCHA correctly, allowing attackers to bypass the challenge via a specially crafted value. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Details The public Registration workflow member.php?action=doregister...