CVE-2026-34463
MantisBT has Stored HTML Injection/XSS via Clone Issue Form
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
MantisBT has Stored HTML Injection/XSS via Clone Issue Form
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.
- Record
CVE-2026-34463- CVSS 4.0
- 8.6 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-30998
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.
- Record
EUVD-2026-30998- CVSS 4.0
- 8.6 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-fvjf-68wh-rwp2
MantisBT is Vulnerable to Stored HTML Injection/XSS in Clone Issue Form
When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level).
Impact
Cross-site scripting (XSS). This is mitigated by Content Security Policy which restricts scripts execution.
Patches
- df22697ae497ddd93f3d9132fdf4979db8d081cd
Workarounds
Make sure Project names do not contain any HTML tags.
Credits
Thanks to Vishal Shukla for discovering and responsibly reporting the issue.
The vulnerability was also identified and independently reported by @siunam321 (Tang Cheuk Hei), prior to this Advisory's publication.
- Record
GHSA-fvjf-68wh-rwp2- CVSS 4.0
- 8.6 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.
- Record
CVE-2026-34463- CVSS 4.0
- 8.6 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
MantisBT has Stored HTML Injection/XSS via Clone Issue Form
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.
- Record
CVE-2026-34463- CVSS 4.0
- 8.6 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVGHSA-fvjf-68wh-rwp2
MantisBT is Vulnerable to Stored HTML Injection/XSS in Clone Issue Form
When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level).
Impact
Cross-site scripting (XSS). This is mitigated by Content Security Policy which restricts scripts execution.
Patches
- df22697ae497ddd93f3d9132fdf4979db8d081cd
Workarounds
Make sure Project names do not contain any HTML tags.
Credits
Thanks to Vishal Shukla for discovering and responsibly reporting the issue.
The vulnerability was also identified and independently reported by @siunam321 (Tang Cheuk Hei), prior to this Advisory's publication.
- Record
GHSA-fvjf-68wh-rwp2- CVSS 4.0
- 8.6 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mantisbt/mantisbtPackagist |
through 2.28.1 | 2.28.2 |
mantisbt/mantisbtPackagist |
before 2.28.2, plus listed versions 2.10.02.10.12.11.02.11.12.12.0 Show 45 moreShow less2.12.12.12.22.13.02.13.12.13.22.14.02.15.02.15.12.16.02.16.12.17.02.17.12.17.22.18.02.18.12.19.02.19.12.20.02.20.12.21.02.21.12.21.22.21.32.22.02.22.12.22.22.23.02.23.12.24.02.24.12.24.22.24.32.24.42.24.52.25.02.25.12.25.22.25.32.25.42.25.52.25.62.25.72.25.82.26.02.26.1 |
2.28.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-34463 is a high vulnerability (CVSS 8.6) in Mantisbt, published May 11, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.44%, the 38th percentile. Fixed in mantisbt/mantisbt 2.28.2.
References
github.com/mantisbt/mantisbt/security/advisories/GHSA-fvjf-68wh-rwp2
mantisbt.org/bugs/view.php?id=36986
nvd.nist.gov/vuln/detail/CVE-2026-34463
Left out here: 26 versions. The JSON record has them.