CVE-2026-27807

MEDIUM

Markus < 2.9.4 - XML External Entity Injection via YAML Alias Parsing

Title source: llm

Description

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.

References (2)

Core 2

Core References

Vendor Advisory x_refsource_confirm

https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6

Release Notes x_refsource_misc

https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4

Scores

CVSS v3 4.9

EPSS 0.0028

EPSS Percentile 19.9%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-776

Status published

Products (1)

markusproject/markus < 2.9.4

Published Mar 06, 2026

Tracked Since Mar 06, 2026