CVE-2026-45116

Published: Ago 18, 2026 Last Modified: Ago 18, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,7
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: required
Scope: changed
Confidentiality: high
Integrity: high
Availability: none

Description

AI Translation Available

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::verify_profile_fields() only performs the specialized validation when is_array($profile_fields[$field]) is true. A non-array profile_fields[fidX] value instead of the expected profile_fields[fidX][] shape falls through to generic text handling and is stored without verification. The affected value is then rendered directly by member.php and inc/functions_post.php rather than processed by the MyCode parser. The uniquely identifying implementation details include inc/datahandlers/user.php. This issue is fixed in version 1.8.40.

79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Confidentiality Integrity Availability
Potential Impacts:
Bypass Protection Mechanism Read Application Data Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies: AI/ML, Web Based, Web Server
Likelihood of Exploit: High
View CWE Details
https://github.com/mybb/mybb/commit/c32f0c22baab704a68b8d58…
https://github.com/mybb/mybb/commit/c32f0c22baab704a68b8d58fcdd2f26fadbbe19b
https://github.com/mybb/mybb/releases/tag/mybb_1840
https://github.com/mybb/mybb/releases/tag/mybb_1840
https://github.com/mybb/mybb/security/advisories/GHSA-4p6g-…
https://github.com/mybb/mybb/security/advisories/GHSA-4p6g-p3qh-559v
https://mybb.com/versions/1.8.40
https://mybb.com/versions/1.8.40