CVE-2026-34579 MantisBT has an authorization bypass via private issue monitoring
Attackers with project access can monitor private issues via crafted requests, receiving email notifications that disclose private issue metadata and content.
- 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-2026-34579?
CVE-2026-34579 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 are vulnerable to Authorization Bypass through the private issue monitoring feature . Using a crafted POST request to bug_monitor_add.php, a user with project-level access can add themselves as a monitor for a private issue they do not have access to. Despite displaying an Access Denied error, the application accepts the request and creates a monitor relationship for the private issue. Direct access to the private issue remains blocked, but the user will receive email notifications for updates, leading to disclosure of the private issue's metadata and content. This issue has been fixed in version 2.28.2.
Which versions are affected by CVE-2026-34579?
2 open source packages ship an affected version, including mantisbt/mantisbt.
| Package | Affected | Fixed in |
|---|---|---|
mantisbt/mantisbt Packagist | From 2.26.1 | 2.28.2 |
mantisbt/mantisbt Packagist | From 2.26.1 | 2.28.2 |
How do I fix CVE-2026-34579?
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-2026-34579 being exploited?
There is no known exploitation of CVE-2026-34579 in the wild and no public exploit code.
Sources
Also known as GHSA-ggw7-9675-6v4v.