CVE-2026-33517 MantisBT Vulnerable to Stored HTML Injection in Tag Delete Confirmation
Attackers can inject HTML and execute JavaScript via tag names in MantisBT, potentially leading to account takeover if CSP allows.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-33517?
CVE-2026-33517 is a high-severity cross-site scripting vulnerability in Mantisbt Mantisbt, published on 23 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Mantis Bug Tracker (MantisBT) is an open source issue tracker. In version 2.28.0, when deleting a Tag (tag_delete.php), improper escaping of its name when displaying the confirmation message allows an attacker to inject HTML and, if CSP settings permit, achieve execution of arbitrary JavaScript. Version 2.28.1 fixes the issue. Workarounds include reverting commit d6890320752ecf37bd74d11fe14fe7dc12335be9 and/or manually editing language files to remove the sprintf placeholder `%1$s` from `$s_tag_delete_message` string.
Weakness: CWE-79
Which versions are affected by CVE-2026-33517?
2 open source packages ship an affected version, including mantisbt/mantisbt. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mantisbt/mantisbt Packagist | From 2.28.0 | 2.28.1 |
mantisbt/mantisbt Packagist | From 2.28.0 | 2.28.1 |
Products include Mantisbt Mantisbt.
How do I fix CVE-2026-33517?
Upgrade mantisbt/mantisbt to 2.28.1 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-33517 being exploited?
There is no known exploitation of CVE-2026-33517 in the wild and no public exploit code.
Other vulnerabilities in Mantisbt Mantisbt
- CVE-2019-15074 MantisBT allows cross-site scripting (XSS) via crafted filename
- CVE-2026-30849 MantisBT SOAP API has an authentication bypass vulnerability on MySQL
- CVE-2025-47776 MantisBT: Authentication bypass for some passwords due to PHP type juggling
- CVE-2017-7615 MantisBT allows arbitrary password reset
- CVE-2026-33548 MantisBT has Stored HTML Injection / XSS when displaying Tags in Timeline
Sources
Also known as GHSA-fh48-f69w-7vmp.