Vulnerability · Published May 7, 2026 · Assigned by GitHub_P
CVE-2026-8106Reflected HTML injection vulnerability in GitHub Enterprise Server Management Console login page allowed credential theft
Medium 5.9
In plain English
A medium-severity cross-site scripting in Enterprise Server from GitHub. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| GitHub | Enterprise Server | 3.19.1 – through 3.19.53.20.0 – through 3.20.1 |
Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N