CVE-2026-45126

low

Description

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Security Questions module does not validate the anti-CSRF token correctly, allowing same-site attackers to enable or disable registration challenge questions with a specially crafted URL. The controller processes GET requests for the disable and enable actions to modify mybb_questions.active without verifying the my_post_key token attached by the user interface. The uniquely identifying implementation details include admin/modules/config/questions.php. This issue is fixed in version 1.8.40.

References

https://mybb.com/versions/1.8.40

https://github.com/mybb/mybb/security/advisories/GHSA-m42q-vgx3-fqcc

https://github.com/mybb/mybb/releases/tag/mybb_1840

https://github.com/mybb/mybb/commit/6893b395c7fa3b9e4de6235caea0ce198c376c4f

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-61007

Details

Source: Mitre, NVD

Published: 2026-08-18

Updated: 2026-09-08

Risk Information

CVSS v2

Base Score: 4

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 3.5

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Severity: Low

EPSS

EPSS: 0.00173