CVE-2026-52847
MantisBT: Reflected XSS in admin/install.php
Description
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 print_test_result(). 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/0f32ceabadc745239754962df91a51d5d51e3fd7 - https://github.com/mantisbt/mantisbt/commit/f2191a0d8ce438bf74171d496cf721dae025a5c0 ### 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-vcrw-4xvv-jh49](https://github.com/mantisbt/mantisbt/security/advisories/GHSA-vcrw-4xvv-jh49) ### Credits McCaulay Hudson (@_McCaulay) of watchTowr
How to fix CVE-2026-52847
To remediate CVE-2026-52847, upgrade the affected package to a fixed version below.
- —upgrade to 2.28.4 or later
Is CVE-2026-52847 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-52847.
Affected packages (1)
- from 0, < 2.28.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N |