XSS in GitHub Enterprise Server
CVE-2026-8106
A reflected HTML injection vulnerability was identified in the GitHub Enterprise Server Management Console login page that could allow credential theft. The redirect_to query parameter on the /setup/unlock endpoint was reflected into an HTML attribute without proper sanitization, enabling an attacker to inject a form element that could capture administrator credentials. Exploitation required an administrator to click a crafted link and enter their credentials. This vulnerability affected GitHub Enterprise Server versions 3.19.1 through 3.19.5 and 3.20.0 through 3.20.1, and was fixed in versions 3.19.6 and 3.20.2. This vulnerability was reported via the GitHub Bug Bounty program.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (16.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- GitHub Enterprise Server — versions 3.19.1, 3.20.0, 3.19.0
- GitHub Enterprise Server
Weakness classification (CWE)
References
- docs.github.com/en/enterprise-server@3.19/admin/release-notes (release-notes, Release Notes, Vendor Advisory)
- docs.github.com/en/enterprise-server@3.20/admin/release-notes (release-notes, Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-8106?
- CVE-2026-8106 is a medium-severity vulnerability in GitHub Enterprise Server, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-05-07.
- How severe is CVE-2026-8106?
- Medium severity. CVSS v3 base score is 6.1 out of 10.