# CVE-2026-40607: MantisBT stored XSS in Saved-Filter Owner column

Source: https://junglewise.ai/threats/cve-2026-40607-mantisbt-stored-xss-in-saved-filter-owner-column  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-11. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-40607 · Severity: high · CVSS 4 · Published 2026-05-11

MantisBT, a popular open-source bug tracking system, is vulnerable to a security flaw where malicious code can be injected into saved filters. If exploited, an attacker could execute unauthorized scripts in the browsers of other users, potentially leading to data theft or account takeover. This issue specifically affects systems where the 'real name' display feature is enabled and typically requires administrative or manager-level privileges to initiate.

Technologies: [MantisBT](https://junglewise.ai/threats/technologies/mantisbt), [mantisbt/mantisbt (Packagist)](https://junglewise.ai/threats/technologies/mantisbt-mantisbt). Vendors: [MantisBT](https://junglewise.ai/threats/vendors/mantisbt), [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2026-40607 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-40607 being exploited in the wild.

**How severe is CVE-2026-40607?** High severity, with a CVSS score of 4, published 11 May 2026.

**Which products and versions are affected?** MantisBT >= 2.1.0, <= 2.28.1; mantisbt/mantisbt (Packagist) >= 2.1.0, <= 2.28.1, ECOSYSTEM:introduced=2.1.0,fixed=2.28.2.

**Is there a fix for CVE-2026-40607?** Yes. mantisbt/mantisbt (Packagist): upgrade to 2.28.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-40607 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-40607?** Check whether you run MantisBT or mantisbt/mantisbt (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- mantisbt/mantisbt (Packagist): upgrade to 2.28.2 or later

  ```sh
  composer require mantisbt/mantisbt:^2.28.2
  ```


## Technical details

A stored cross-site scripting (XSS) vulnerability exists in MantisBT due to incorrect escaping of a saved filter's owner name. The vulnerability is triggered when the configuration option '$g_show_user_realname' is set to ON, allowing an attacker to inject arbitrary HTML/JavaScript via the owner column. While the attack vector is network-based, exploitation typically requires 'Manager' access level or higher to save filters publicly. Successful exploitation allows for arbitrary code execution in the context of a victim's browser session. A patch has been released in version 2.28.2, and workarounds include disabling the real name display or restricting filter creation permissions.

## Affected products

- MantisBT MantisBT >= 2.1.0, <= 2.28.1

## Identifiers

- CVE-2026-40607
- GHSA-f633-865q-2mhh

## Timeline

- 2026-05-11: disclosed
- 2026-05-11: advisory

## References

- [https://api.github.com/users/siunam321](https://api.github.com/users/siunam321)
- [https://github.com/siunam321](https://github.com/siunam321)
- [https://api.github.com/users/siunam321/gists%7B/gist_id%7D](https://api.github.com/users/siunam321/gists%7B/gist_id%7D)
- [https://api.github.com/users/siunam321/repos](https://api.github.com/users/siunam321/repos)
- [https://avatars.githubusercontent.com/u/104430134?v=4](https://avatars.githubusercontent.com/u/104430134?v=4)
- [https://api.github.com/users/siunam321/events%7B/privacy%7D](https://api.github.com/users/siunam321/events%7B/privacy%7D)

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- [MantisBT authentication bypass in SOAP API](https://junglewise.ai/threats/cve-2026-47156-mantisbt-authentication-bypass-in-soap-api)
- [MantisBT stored XSS in print_all_bug_page_word.php](https://junglewise.ai/threats/cve-2026-62944-mantisbt-stored-xss-in-print-all-bug-page-word-php)
- [MantisBT improper input validation in REST and SOAP APIs](https://junglewise.ai/threats/cve-2026-52883-mantisbt-improper-input-validation-in-rest-and-soap-apis)
- [MantisBT authorization bypass in REST and SOAP APIs](https://junglewise.ai/threats/cve-2026-52882-mantisbt-authorization-bypass-in-rest-and-soap-apis)
- [MantisBT reflected XSS in admin/install.php](https://junglewise.ai/threats/cve-2026-52881-mantisbt-reflected-xss-in-admin-install-php)