CVE-2026-33548
MantisBT has Stored HTML Injection/XSS when displaying Tags in Timeline
Description
Improper escaping of tag names retrieved from History in Timeline (my_view_page.php) allows an attacker to inject HTML and, if CSP settings permit, achieve execution of arbitrary JavaScript, when displaying a tag that has been renamed or deleted. ### Impact Cross-site scripting (XSS). ### Patches f32787c14d4518476fe7f05f992dbfe6eaccd815 ### Workarounds * Edit offending History entries (using SQL) * Wrap `$this->tag_name` in a string_html_specialchars() call in IssueTagTimelineEvent::html() ### Credits MantisBT thanks Vishal Shukla for discovering and responsibly reporting the issue.
How to fix CVE-2026-33548
To remediate CVE-2026-33548, upgrade the affected package to a fixed version below.
- —upgrade to 2.28.2 or later
Is CVE-2026-33548 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 2.28.0, < 2.28.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |