CVE-2026-45126

MyBB: ACP Questions state CSRF

LOW
3.5
CVSS Score
Published: August 18, 2026 at 03:47 PM UTC
Updated: September 8, 2026 at 09:19 PM UTC
1 product affected across 1 vendorMybb

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Severity
LOW3.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.8.40
Affected range stops below 1.8.40, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

3.5LOWGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-352

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