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-2026-45116 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: 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-2026-45115 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-2026-45115

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-2026-45115 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...

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 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...

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...

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...

CVE-2026-46482

MyBB's registration flow (member.php?action=do_register) accepts a hidden question_id field and validates the Security Question answer without a fail-closed fallback. A blank, forged, or expired question_id lets the request proceed, enabling CAPTCHA bypass for automated account creation. CVSS 3.1...

CVE-2026-45123 MyBB: IPv6 SSRF

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetchremotefile...

CVE-2026-45123

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetchremotefile...

CVE-2026-45123 MyBB: IPv6 SSRF

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetchremotefile...

EUVD-2026-61051

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetchremotefile...