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MarkusApplication · Markusproject

CVE-2026-25962

MEDIUM · 6.5 CVSS v3.1 Published 2026-03-06
Fix available
A fix is available. Upgrade to 2.9.4 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs currently extracts zip files without any size or entry-count limits. For example, instructors can upload a zip file to provide an assignment configuration; students can upload a zip file for an assignment submission and indicate its contents should be extracted. This issue has been patched in version 2.9.4.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

MarkUs versions prior to 2.9.4 lack validation when extracting uploaded ZIP files, allowing unlimited file sizes and entry counts during extraction. This enables resource exhaustion attacks via ZIP bombs or excessive disk consumption when students/instructors upload ZIP files for assignment submissions or configuration.

MitigationUpgrade to MarkUs version 2.9.4 or later which implements size and entry-count limits for ZIP extraction. If immediate upgrade is not possible, implement application-level limits on ZIP file size and number of entries before extraction.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MarkusApplication
Affected:< 2.9.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed MarkUs version
    Locate the MarkUs version file, gem specification, or access the application About page (typically /about) to retrieve the running version number
    Affected if The installed version is prior to 2.9.4
  2. Confirm ZIP upload feature is in use
    Check if assignment submissions or configuration allow ZIP file uploads by reviewing the application's submission settings or testing file upload functionality
    Affected if Users can upload ZIP files for assignments or configuration purposes
  3. Verify ZIP extraction limits exist
    Search application configuration files (such as config/application.rb, config/environments/*.rb, or initializers) for parameters that limit ZIP file size or entry count during extraction
    Affected if No extraction limits are configured or the application lacks code to validate ZIP file sizes and entry counts before extraction
  4. Check for ZIP bomb protection
    Inspect the ZIP extraction code in the codebase (likely in models or controllers handling file uploads) for explicit validation of compression ratios or entry limits
    Affected if The extraction routine performs no validation of zip entry count or decompressed size limits

You are affected if the installed MarkUs version is below 2.9.4 AND the application accepts ZIP file uploads for assignments or configuration without extraction limits in place.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.9.4 or later
Fixed in 2.9.4
Interim mitigation

Upgrade to MarkUs version 2.9.4 or later which implements size and entry-count limits for ZIP extraction. If immediate upgrade is not possible, implement application-level limits on ZIP file size and number of entries before extraction.

Recommended fix Moderate confidence

2.9.4

  1. Verify current installed version of MarkUs by checking the application or configuration files
  2. Backup the current MarkUs installation and database before proceeding with the upgrade
  3. Upgrade MarkUs to version 2.9.4 or later by following the project's upgrade documentation (typically involves pulling the latest release or updating the gem/pip packages)
  4. Verify that zip file extraction now includes size and entry-count limits
  5. Test the zip upload functionality to confirm the fix works as expected
  6. Monitor application logs for any extraction-related errors
Caveat Review release notes for 2.9.4 to check for any configuration or dependency changes; minor version upgrades in MarkUs typically have low breaking change risk

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Markus Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-25962 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data