CVE-2026-40607 MantisBT is Vulnerable to Stored XSS Through its Saved-Filter Owner Column
Attackers can inject arbitrary HTML via saved filter owners in MantisBT, potentially leading to session hijacking or malicious script execution.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40607?
CVE-2026-40607 is a high-severity cross-site scripting vulnerability in mantisbt, published on 22 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.11.0 through 2.28.1, a Stored XSS vulnerability is caused by incorrect escaping of a saved filter's owner, allowing an attacker to inject arbitrary HTML on systems where $g_show_user_realname = ON. Note that By default, only users with Manager access level or above can save their filters publicly. This issue has been fixed in version 2.28.2. If developers are unable to update immediately, they can work around this issue by preventing display of users' real names (set $g_ show_user_realname = OFF; in configuration), and restricting the ability to store filters (set $g_stored_query_create_threshold / $g_stored_query_create_shared_threshold to NOBODY).
Weakness: CWE-79
Which versions are affected by CVE-2026-40607?
2 open source packages ship an affected version, including mantisbt/mantisbt.
| Package | Affected | Fixed in |
|---|---|---|
mantisbt/mantisbt Packagist | From 2.1.0 | 2.28.2 |
mantisbt/mantisbt Packagist | From 2.1.0 | 2.28.2 |
How do I fix CVE-2026-40607?
Upgrade mantisbt/mantisbt to 2.28.2 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-40607 being exploited?
There is no known exploitation of CVE-2026-40607 in the wild and no public exploit code.
Sources
Also known as GHSA-f633-865q-2mhh.