CVE-2026-45119

4.6 MEDIUM 0.2% exploit odds Fix listed Auth & access Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account, but needs a user to act. Limited direct impact.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-18 16:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-08 21:02 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 4.6 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-08-18 16:17 UTC
Last modified: 2026-09-08 21:02 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-352 · Cross-site request forgery
Record status: Deferred

Attack profile CVSS 3.1 · 4.6

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: Low

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-45119.md and follow it. Check whether this project is affected by CVE-2026-45119. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record