What’s Vulnerable › Vulnerabilities

CVE-2026-24900: MarkUs has a submission-view IDOR exposes all student submissions

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-09 · updated 2026-06-17
• Weakness: CWE-639

Description

MarkUs is a web application for the submission and grading of student assignments. Prior to 2.9.1, the courses/<:course_id>/assignments/<:assignment_id>/submissions/html_content accepted a select_file_id parameter to serve SubmissionFile objects containing a record of files submitted by students. This parameter was not correctly scoped to the requesting user, allowing users access arbitrary submission file contents by id. This vulnerability is fixed in 2.9.1.

Affected products

• MarkUsProject Markus: before 2.9.1 — fixed in 2.9.1

How to fix

Upgrade to a fixed version: MarkUsProject Markus 2.9.1. Check the vendor advisory for mitigations.

References

• https://github.com/MarkUsProject/Markus/commit/7daed9fd2d44932223798d997b55094a3bff104b
• https://github.com/MarkUsProject/Markus/releases/tag/v2.9.1
• https://github.com/MarkUsProject/Markus/security/advisories/GHSA-56gh-8hmq-7q88

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