---
id: CVE-2026-52881
aliases:
  - GHSA-vcrw-4xvv-jh49
title: 'MantisBT: Reflected XSS in admin/install.php via unescaped printf '
summary: 'MantisBT: Reflected XSS in admin/install.php via unescaped printf '
severity: critical
cwe:
  - CWE-79
vendor: mantisbt
product: mantisbt/mantisbt
ecosystem: composer
affected:
  - mantisbt/mantisbt <= 2.28.3
patched:
  - mantisbt/mantisbt 2.28.4
published: '2026-07-15'
updated: '2026-07-15'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-vcrw-4xvv-jh49'
references:
  - url: >-
      https://github.com/mantisbt/mantisbt/security/advisories/GHSA-vcrw-4xvv-jh49
  - url: >-
      https://github.com/mantisbt/mantisbt/commit/297773fbb238c39a153bd888431b41a176132098
  - url: 'https://mantisbt.org/bugs/view.php?id=37103'
  - url: 'https://github.com/advisories/GHSA-vcrw-4xvv-jh49'
tags:
  - ghsa
  - composer
ingestedAt: '2026-07-15T18:45:16.852Z'
---

## Overview

MantisBT 2.28.3 and earlier contains six reflected XSS injection points in `/admin/install.php`. User-supplied parameters are echoed into HTML without escaping via an unescaped printf format string. No authentication is required.

A Content Security Policy (script-src 'self') prevents inline JavaScript execution, but the CSP is missing a form-action directive, allowing exploitation via credential-phishing form injection and <meta> open redirects.

### Impact
- Credential phishing: Attacker crafts a URL that renders a fake login form on the real MantisBT admin page. Admin credentials are submitted to an attacker-controlled server.
- Open redirect: Victim is silently redirected to a phishing or malware site.
- UI manipulation: CSS injection can hide legitimate page content and overlay attacker-controlled HTML, enabling social engineering.

### Patches
- https://github.com/mantisbt/mantisbt/commit/297773fbb238c39a153bd888431b41a176132098

### Workarounds
Remove the `/admin` directory, as [recommended in the Admin Guide](https://mantisbt.org/docs/master/en-US/Admin_Guide/html-desktop/#admin.install.postcommon)

### Resources
- https://mantisbt.org/bugs/view.php?id=37103
- related advisory [GHSA-77x8-3v3h-hrhv](https://github.com/mantisbt/mantisbt/security/advisories/GHSA-77x8-3v3h-hrhv)

### Credits
McCaulay Hudson (@_McCaulay) of watchTowr

## Affected packages

- `mantisbt/mantisbt <= 2.28.3`

## Remediation

Upgrade to a patched release:

- `mantisbt/mantisbt 2.28.4`