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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-45118 Detail

Description

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/mybb/mybb/releases/tag/mybb_1840 GitHub, Inc.
https://github.com/mybb/mybb/security/advisories/GHSA-wf92-5q5h-qr53 GitHub, Inc.
https://mybb.com/versions/1.8.40 GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-83 Improper Neutralization of Script in Attributes in a Web Page GitHub, Inc.  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-45118
NVD Published Date:
08/18/2026
NVD Last Modified:
08/18/2026
Source:
GitHub, Inc.