Zip Slip in MarkUs config upload allowing RCE
Priority MEDIUM 42CWE-23Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00546 45th percentileScored 2026-11-07
Fix Fixed Markus (MarkUsProject): 2.9.1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| MarkUsProject | Markus | before 2.9.1 | 2.9.1 | Patch available | CNA |
- Markus VendorMarkUsProject Affected before 2.9.1 Fixed in 2.9.1 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:markusproject:markus:*:*:*:*:*:*:*:* | before 2.9.1 | Vulnerable | MarkUsProject |
- cpe:2.3:a:markusproject:markus:*:*:*:*:*:*:*:* Versions before 2.9.1 Vulnerable ·MarkUsProject
Remediation
- Fix · CNA Markus (MarkUsProject) Fixed in 2.9.1
Timeline
- 2026-10-02 Threatist record created from CVE-2026-25057
References
More MarkUsProject Markus vulnerabilities
- TI-2026-22679 MarkUs: Stored XSS in Submission HTML Preview Enables Instructor-Context Actions CVSS 3.1HIGH 8.0
- TI-2024-34648 Arbitrary File Write leading up to remote code execution (instructor accounts) CVSS 4.0HIGH 7.1
- TI-2024-34420 MarkUs Arbitrary File Write leading up to remote code execution (student accounts) CVSS 4.0HIGH 7.1
- TI-2026-20987 MarkUs: Zip bomb in config upload enables DoS CVSS 3.1MEDIUM 6.5
- TI-2026-20085 MarkUs has a submission-view IDOR exposes all student submissions CVSS 3.1MEDIUM 6.5
- TI-2024-32087 MarkUs vulnerable to Path Traversal CVSS 3.1MEDIUM 5.7
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences