CVE-2026-2266

MEDIUM

5.4

Description

An improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed DOM-based cross-site scripting via task list content. The task list content extraction logic did not properly re-encode browser-decoded text nodes before rendering, allowing user-supplied HTML to be injected into the page. An authenticated attacker could craft malicious task list items in issues or pull requests to execute arbitrary scripts in the context of another user's browser session. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.18.6 and 3.19.3. This vulnerability was reported via the GitHub Bug Bounty program.

CVE Details

CVSS v3.1 Score5.4

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredLOW

User InteractionREQUIRED

Published3/10/2026

Last Modified3/12/2026

Sourcenvd

Honeypot Sightings0

Affected Products

github:enterprise_server

Weaknesses (CWE)

CWE-79

References

https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.6(product-cna@github.com)

https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.3(product-cna@github.com)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.