CVE intelligence and bounded remediation
CVE-2026-24900 — MarkUs is a web application for the submission and grading of student assignments
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.
- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Published
- 2026-02-09
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-639
Affected products
- markusproject / markus
Matched remediation archetype
Authorization bypass, IDOR, and cross-tenant access
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
- Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
- Use synthetic fixtures to compare intended access matrices without accessing another user's real data.
Remediate safely
- Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
- Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
- Add deny-by-default policy tests for horizontal and vertical access across every affected transport.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.