CVE-2026-8106
HTML Injection in GitHub Enterprise Server Management Console
Publication date: 2026-05-07
Last updated on: 2026-05-07
Assigner: GitHub, Inc. (Products Only)
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| github | enterprise_server | From 3.19.1 (inc) to 3.19.5 (inc) |
| github | enterprise_server | From 3.20.0 (inc) to 3.20.1 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a reflected HTML injection found in the GitHub Enterprise Server Management Console login page. Specifically, the redirect_to query parameter on the /setup/unlock endpoint is reflected into an HTML attribute without proper sanitization. This flaw allows an attacker to inject a form element that can capture administrator credentials.
To exploit this vulnerability, an attacker would need to craft a malicious link and trick an administrator into clicking it and entering their credentials, which could then be stolen.
The 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.
How can this vulnerability impact me? :
This vulnerability can lead to credential theft of administrator accounts if exploited. An attacker who successfully tricks an administrator into clicking a crafted link and entering their credentials could capture those credentials.
Compromise of administrator credentials can lead to unauthorized access to the GitHub Enterprise Server, potentially allowing the attacker to manipulate repositories, access sensitive data, or disrupt services.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade your GitHub Enterprise Server to version 3.19.6 or later if you are running any version from 3.19.1 through 3.19.5, or to version 3.20.2 or later if you are running versions 3.20.0 through 3.20.1.
Additionally, advise administrators to avoid clicking on suspicious or untrusted links that could exploit the reflected HTML injection vulnerability on the /setup/unlock endpoint.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows an attacker to inject malicious HTML to capture administrator credentials by exploiting a reflected HTML injection flaw in the GitHub Enterprise Server Management Console login page.
Credential theft incidents can lead to unauthorized access to sensitive data, which may result in non-compliance with data protection regulations such as GDPR and HIPAA that require safeguarding user credentials and preventing unauthorized access.
Therefore, exploitation of this vulnerability could potentially compromise compliance with standards that mandate strict access controls and protection of personal and sensitive information.