CVE-2026-45115

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 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 Messages pass usernames through htmlspecialchars_uni(), which may leave single quotes unescaped. The payload is triggered when a victim chooses Yes in Please Confirm while removing the username in usercp.php, or selects the username through the onclick handler in the xmlhttp.php Select Buddies popup. The uniquely identifying implementation details include Private Messages Select Buddies list, and unescaped single quotes. 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/releases/tag/mybb_1840
https://github.com/mybb/mybb/releases/tag/mybb_1840
https://github.com/mybb/mybb/security/advisories/GHSA-p766-…
https://github.com/mybb/mybb/security/advisories/GHSA-p766-qqxv-rfc2
https://mybb.com/versions/1.8.40
https://mybb.com/versions/1.8.40