Low 3.5Published Aug 18, 2026

CVE-2026-45128MyBB: ACP Users View Manager default CSRF

Updated under an hour ago (2026-10-19 09:40 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

MyBB is free and open source forum software. Prior to 1.8.40, the ACP Users View Manager module does not validate requests correctly, allowing same-site attackers to change a victim administrator's default user list view by embedding a specially crafted URL. The Set as Default control named set_default in Admin CP, Users & Groups, Users, View Manager changes the administrator's default view on GET requests without request forgery protection. The uniquely identifying implementation details include Users & Groups → Users → View Manager, and admin/inc/functions_view_manager.php. This issue is fixed in version 1.8.40.

CVSS: 3.5 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-352
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Aug 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mybb mybb mybb:mybb (from the name)	before 1.8.40	CNA record

References

https://github.com/mybb/mybb/security/advisories/GHSA-m6hr-25cj-p58qx-refsource-confirm
https://github.com/mybb/mybb/commit/736a2bcbc7cc104df8ae6c0a160aa3917a1ceec0x-refsource-misc
https://github.com/mybb/mybb/releases/tag/mybb_1840x-refsource-misc
https://mybb.com/versions/1.8.40x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.