CVE-2026-45126Network attack vector

Question-state tampering via unchecked my_post_key

Published Aug 18, 2026 · Updated Aug 18, 2026

CSRF in the Admin CP Security Questions module in MyBB before 1.8.40 allows attackers to change question status via crafted URLs. In admin/modules/config/questions.php, the enable and disable handlers accept GET requests that update mybb_questions.active and never call verify_post_check on the my_post_key token added by the interface. Exploitation requires an authenticated administrator to follow or render an attacker-controlled same-site request; the exposed action is limited to enabling or disabling registration challenge questions.

CVSS severity3.5
Low
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in the Admin CP Security Questions module in MyBB before 1.8.40 allows attackers to change question status via crafted URLs. In admin/modules/config/questions.php, the enable and disable handlers accept GET requests that update mybb_questions.active and never call verify_post_check on the my_post_key token added by the interface. Exploitation requires an authenticated administrator to follow or render an attacker-controlled same-site request; the exposed action is limited to enabling or disabling registration challenge questions.

The record

CVE
CVE-2026-45126
Published
Aug 18, 2026
Updated
Aug 18, 2026
Vendor
MyBB
Product
MyBB
Classifications
CWE-352
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.8.40

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MyBB · MyBBversion=< 1.8.40

Published CVSS scores

3.5GitHub_MCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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