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

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.

Published: 2026-02-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-24900 is rated Low Risk (31.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.25%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-24900

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.25% +0.20%
2 2026-06-11 0.03% 0.05% +0.02%
3 2026-02-10 0.03%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-24900

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-24900

Affected software / configurations for CVE-2026-24900

Vendor Product Version Raw CPE
markusproject markus < 2.9.1 cpe:2.3:a:markusproject:markus:*:*:*:*:*:*:*:*

References for CVE-2026-24900

cvelogic Threat Intelligence