# CVE-2026-52847: MantisBT reflected XSS in admin/install.php

Source: https://junglewise.ai/threats/cve-2026-52847-mantisbt-reflected-xss-in-admin-install-php  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-15. Updated: 2026-07-15  
License: CC BY 4.0 with a link back

CVE-2026-52847 · Severity: critical · CVSS 4 · Published 2026-07-15

MantisBT, a popular open-source bug tracking system, contains a vulnerability in its installation component. An attacker can use this flaw to display fake login forms or redirect users to malicious websites. This could lead to the theft of administrator credentials or the spread of malware, potentially compromising the entire bug tracking system and its data.

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

## Quick answers

**Is CVE-2026-52847 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-52847 being exploited in the wild.

**How severe is CVE-2026-52847?** Critical severity, with a CVSS score of 4, published 15 July 2026.

**Which products and versions are affected?** mantisbt/mantisbt (Packagist) <= 2.28.3, ECOSYSTEM:introduced=0,fixed=2.28.4.

**Is there a fix for CVE-2026-52847?** Yes. mantisbt/mantisbt (Packagist): upgrade to 2.28.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-52847 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-52847?** Check whether you run 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 2.28.4 or later

  ```sh
  composer require mantisbt/mantisbt:^2.28.4
  ```


## Technical details

MantisBT 2.28.3 and earlier contains six reflected XSS injection points in /admin/install.php due to user-supplied parameters being echoed into HTML without escaping via the print_test_result() function. While a Content Security Policy (CSP) is present, it lacks a form-action directive, which allows attackers to bypass script execution restrictions to perform credential phishing via form injection, CSS-based UI manipulation, and <meta> tag open redirects. No authentication is required for exploitation. The vulnerability is addressed in version 2.28.4; a recommended workaround is to remove the /admin directory after installation.

## Affected products

- MantisBT MantisBT <= 2.28.3

## Identifiers

- CVE-2026-52847
- GHSA-77x8-3v3h-hrhv

## Timeline

- 2026-07-15: disclosed
- 2026-07-15: patched: Fixed in version 2.28.4
- 2026-07-15: advisory

## References

- [https://api.github.com/users/McCaulay](https://api.github.com/users/McCaulay)
- [https://github.com/McCaulay](https://github.com/McCaulay)
- [https://api.github.com/users/McCaulay/gists%7B/gist_id%7D](https://api.github.com/users/McCaulay/gists%7B/gist_id%7D)
- [https://api.github.com/users/McCaulay/repos](https://api.github.com/users/McCaulay/repos)
- [https://avatars.githubusercontent.com/u/31845045?v=4](https://avatars.githubusercontent.com/u/31845045?v=4)
- [https://api.github.com/users/McCaulay/events%7B/privacy%7D](https://api.github.com/users/McCaulay/events%7B/privacy%7D)

## Related threats

- [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)