CVE-2026-34463 HIGH

CVE-2026-34463: MantisBT has Stored HTML Injection/XSS via Clone Issue Form

Vendor Mantisbt
Product mantisbt
Weakness CWE-79 · XSS
Published May 19, 2026
Last update May 20, 2026
View on NVD All CVEs

CVSS base score

8.6/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.

Key dates

02Disclosure timeline

May 19, 2026 CVE published
May 20, 2026 Record updated