What is the CVSS score of CVE-2026-27807?

CVE-2026-27807 has a CVSS 3.1 base score of 4.9 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of Markus are affected by CVE-2026-27807?

Organizations using MarkUs should be aware of moderate risk from CVE-2026-27807 rated CVSS 4.9. Exploitation could compromise the security of affected deployments.

How to fix or mitigate CVE-2026-27807?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Markus CVE-2026-27807

MEDIUM

Improper Restriction of Recursive Entity References in DTDs (CWE-776)

2026-03-06 security-advisories@github.com

XXE Denial Of Service Markus

4.9

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

4.9 MEDIUM

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 06, 2026 - 04:16 nvd

MEDIUM 4.9

DescriptionGitHub Advisory

MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.

AnalysisAI

Markus versions up to 2.9.4 is affected by improper restriction of recursive entity references in dtds (CVSS 4.9).

Technical ContextAI

This vulnerability (CWE-776: Improper Restriction of Recursive Entity References in DTDs) affects Markus. MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.