Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Checkout DevGuardView on GitHub
Search

GHSA-77x8-3v3h-hrhv

CriticalCVSS 9.2 / 10
Published Jul 15, 2026·Last modified Jul 15, 2026
Affected Components(0)

No affected components available

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

Resources

Credits

McCaulay Hudson (@_McCaulay) of watchTowr

Risk Scores
Base Score
9.2

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
7.1

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Critical severity
Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard