CVE-2026-45126
MyBB: ACP Questions state CSRF
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
MyBB: ACP Questions state CSRF
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.
- Record
CVE-2026-45126- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
EUVDEUVD-2026-61007
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.
- Record
EUVD-2026-61007- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-45126- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
OSV
MyBB: ACP Questions state CSRF
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.
- Record
CVE-2026-45126- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-45126 is a low vulnerability (CVSS 3.5) in Mybb, published August 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. No source names a fixed version.
References
github.com/mybb/mybb/security/advisories/GHSA-m42q-vgx3-fqcc
mybb.com/versions/1.8.40
nvd.nist.gov/vuln/detail/CVE-2026-45126