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CVE-2026-45118 (GCVE-0-2026-45118)

Vulnerability from cvelistv5 – Published: 2026-08-18 15:55 – Updated: 2026-08-18 17:52
VLAI
Title
MyBB: Contact page reflected XSS
Summary
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.
Severity
9.3 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-18 17:47 UTC
CWE
  • CWE-83 - Improper Neutralization of Script in Attributes in a Web Page
Assigner
References
Impacted products
Vendor Product Version CPE status
mybb mybb Affected: < 1.8.40
guessed Create a notification for this product.
Show details on NVD website
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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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