Vulnerability · Published May 19, 2026 · Assigned by GitHub_M

CVE-2026-34579MantisBT has an authorization bypass via private issue monitoring

Medium 5.3

In plain English

A medium-severity incorrect authorization in mantisbt from mantisbt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.3Medium

Exploit odds (30 days)0.4%top 69.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	mantisbt/mantisbt	2.28.2	GHSA-ggw7-9675-6v4v

Affected products (as reported)

Vendor	Product	Versions
mantisbt	mantisbt	< 2.28.2

Weakness: CWE-863, CWE-200 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://github.com/mantisbt/mantisbt/security/advisories/GHSA-ggw7-9675-6v4v x_refsource_CONFIRM
https://github.com/mantisbt/mantisbt/commit/0a93267deba445fb9d15250c16e6fdb1246ffa65 x_refsource_MISC
https://mantisbt.org/bugs/view.php?id=36975 x_refsource_MISC