CVE-2026-27807: Markusproject Markus

Medium severity, CVSS 4.9. EPSS: 0.5% chance of exploitation in the next 30 days.

MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.

Affected products

• Markusproject Markus: before 2.9.4 (fixed in 2.9.4)

Published 2026-03-06. Last modified 2026-06-17.