CVE-2026-45118
CRITICAL
9,3
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
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 Contact module does not validate a redirect URL or protocol correctly, resulting in an open redirect and reflected JavaScript code injection. contact.php accepts the redirect target from the from HTTP parameter in $mybb->input['from'] or the Referer HTTP header in $_SERVER['HTTP_REFERER'] and passes it to redirect() without sufficient verification. A javascript: URI becomes the target of the `Click here if you don't want to wait any longer` link because $force_redirect is true, allowing script execution when a victim selects the link. This issue is fixed in version 1.8.40.
83
Improper Neutralization of Script in Attributes in a Web Page
DraftCommon Consequences
Security Scopes Affected:
Confidentiality
Integrity
Availability
Potential Impacts:
Read Application Data
Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies:
Web Based, Web Server
https://github.com/mybb/mybb/releases/tag/mybb_1840
https://github.com/mybb/mybb/security/advisories/GHSA-wf92-5q5h-qr53
https://mybb.com/versions/1.8.40