What’s Vulnerable › Vulnerabilities

CVE-2026-25057: Zip Slip in MarkUs config upload allowing RCE

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-09 · updated 2026-06-17
• Weakness: CWE-23

Description

MarkUs is a web application for the submission and grading of student assignments. Prior to 2.9.1, instructors are able to upload a zip file to create an assignment from an exported configuration (courses/<:course_id>/assignments/upload_config_files). The uploaded zip file entry names are used to create paths to write files to disk without checking these paths. This vulnerability is fixed in 2.9.1.

Affected products

• MarkUsProject Markus: before 2.9.1 — fixed in 2.9.1

How to fix

Upgrade to a fixed version: MarkUsProject Markus 2.9.1. Check the vendor advisory for mitigations.

References

• https://github.com/MarkUsProject/Markus/commit/0ca002a1f0071c7a00dbb2ed34fede57323c5dc7
• https://github.com/MarkUsProject/Markus/releases/tag/v2.9.1
• https://github.com/MarkUsProject/Markus/security/advisories/GHSA-mccg-p332-252h

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