CVE-2026-34463
CVE-2026-34463 is a high-severity vulnerability with a CVSS 4.0 base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.
Key facts
- Severity: High (CVSS 4.0 base score 8.6)
- EPSS exploit prediction: 0% (36th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-30998
- Weakness: CWE-79
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is CVE-2026-34463?
- 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.
- How severe is CVE-2026-34463?
- CVE-2026-34463 has a CVSS 4.0 base score of 8.6, rated high severity.
- Is CVE-2026-34463 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-34463?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-34463 have an EU (EUVD) identifier?
- Yes. CVE-2026-34463 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30998.
- When was CVE-2026-34463 published?
- CVE-2026-34463 was published on 2026-05-19 and last updated on 2026-06-17.
References
- https://github.com/mantisbt/mantisbt/commit/df22697ae497ddd93f3d9132fdf4979db8d081cd
- https://github.com/mantisbt/mantisbt/security/advisories/GHSA-fvjf-68wh-rwp2
- https://mantisbt.org/bugs/view.php?id=36986
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