CVE-2026-28405
High
Description
MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.1, the courses/<:course_id>/assignments/<:assignment_id>/submissions/html_content route reads the contents of a student-submitted file and renders them without sanitization. This issue has been patched in version 2.9.1.
SeverityHigh
CVSS8.0
Exploit probability—
ProductMarkus
PublishedMar 5, 2026
First seenMar 5, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Update
- markusproject markus2.9.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| markusproject markus | v < 2.9.1 | 2.9.1 |
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