CVE-2026-45119 MyBB: ACP UTF-8 Conversion CSRF
Attackers can trigger database table encoding changes and service disruption via CSRF in the Admin CP UTF-8 Conversion module.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-45119?
CVE-2026-45119 is a medium-severity vulnerability in mybb, published on 18 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP UTF-8 Conversion module does not validate certain requests correctly, allowing same-site attackers to alter table encoding and deny service with a specially crafted URL. The do=all control flow in admin/modules/tools/system_health.php performs ALTER TABLE operations, column rewrite phases, and fulltext index rebuilds on GET requests for the database table named by the table parameter without request verification. The uniquely identifying implementation details include GET requests without request verification. This issue is fixed in version 1.8.40.
Weakness: CWE-352
Which versions are affected by CVE-2026-45119?
How do I fix CVE-2026-45119?
No fix has been published for CVE-2026-45119 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-45119 being exploited?
There is no known exploitation of CVE-2026-45119 in the wild and no public exploit code.
Sources
Also known as GHSA-p48q-4vgf-q7x8.