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OpenAdvisories
High · 8.0 CVE-2026-28405 EUVD-2026-9870

MarkUs: Stored XSS in Submission HTML Preview Enables Instructor-Context Actions

Published Mar 5, 2026 · Updated Mar 6, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
MarkUsProject Markus < 2.9.1 —

References