What is CVE-2026-33517?

CVE-2026-33517 is a medium-severity vulnerability in Mantisbt, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-23.

How severe is CVE-2026-33517?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Mantisbt

CVE-2026-33517

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (15.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Mantisbt — versions = 2.28.0, 2.28.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Patch, Mitigation, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-33517?: CVE-2026-33517 is a medium-severity vulnerability in Mantisbt, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-23.
How severe is CVE-2026-33517?: Medium severity. CVSS v3 base score is 6.1 out of 10.