CVE-2026-24900Network attack vector

Authenticated submission disclosure via unscoped file ID

Published Feb 9, 2026 · Updated Feb 9, 2026

IDOR in MarkUs before 2.9.1 allows remote authenticated users to read arbitrary student submission files via a file ID. The html_content action passes select_file_id directly to SubmissionFile.find without scoping the resulting record to the requesting user, course, or assignment. Any authenticated user who knows or guesses another submission file's numeric ID can read its contents, with no reported ability to alter files or interrupt service.

CVSS severity6.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

IDOR in MarkUs before 2.9.1 allows remote authenticated users to read arbitrary student submission files via a file ID. The html_content action passes select_file_id directly to SubmissionFile.find without scoping the resulting record to the requesting user, course, or assignment. Any authenticated user who knows or guesses another submission file's numeric ID can read its contents, with no reported ability to alter files or interrupt service.

The record

CVE
CVE-2026-24900
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
MarkUs Project
Product
MarkUs
Classifications
CWE-639, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MarkUs Project · MarkUsversion=< 2.9.1

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1213Data from Information Repositories

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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