CVE-2026-34754 MantisBT allows unauthorized users to upload attachments to restricted issues via REST API
Authenticated attackers can upload attachments to private issues they lack access to, compromising data integrity in MantisBT.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34754?
CVE-2026-34754 is a medium-severity missing authorization vulnerability in mantisbt, published on 19 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior allow an authenticated user to upload attachments to private Issues they are not authorized to access. This issue has been fixed in version 2.28.2.
Weakness: CWE-284
Which versions are affected by CVE-2026-34754?
2 open source packages ship an affected version, including mantisbt/mantisbt.
| Package | Affected | Fixed in |
|---|---|---|
mantisbt/mantisbt Packagist | All versions | 2.28.2 |
mantisbt/mantisbt Packagist | All versions | 2.28.2 |
How do I fix CVE-2026-34754?
Upgrade mantisbt/mantisbt to 2.28.2 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-34754 being exploited?
There is no known exploitation of CVE-2026-34754 in the wild and no public exploit code.
Sources
Also known as GHSA-h4x5-gvx6-3rwc.