Vulnerability · Published Feb 9, 2026 · Assigned by GitHub_M

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

Medium 6.5

In plain English

A medium-severity authorization bypass via user-controlled key in Markus from MarkUsProject. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 77.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
MarkUsProject	Markus	< 2.9.1

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

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