CVE-2026-8106: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitHub Enterprise Server
CVE-2026-8106 is a reflected cross-site scripting (XSS) vulnerability in the GitHub Enterprise Server Management Console login page. The issue arises from improper sanitization of the redirect_to query parameter on the /setup/unlock endpoint, allowing injection of malicious HTML elements. An attacker could exploit this by tricking an administrator into clicking a crafted link and entering credentials, potentially leading to credential theft. This vulnerability affects GitHub Enterprise Server versions 3.19.1 through 3.19.5 and 3.20.0 through 3.
AI Analysis
Technical Summary
A reflected HTML injection vulnerability (CWE-79) exists in the GitHub Enterprise Server Management Console login page due to improper neutralization of the redirect_to query parameter on the /setup/unlock endpoint. This parameter is reflected into an HTML attribute without proper sanitization, enabling an attacker to inject a form element that can capture administrator credentials. Exploitation requires user interaction by an administrator clicking a crafted link and submitting credentials. The vulnerability affects versions 3.19.1 through 3.19.5 and 3.20.0 through 3.20.1 of GitHub Enterprise Server and was addressed in versions 3.19.6 and 3.20.2. The vulnerability was reported through the GitHub Bug Bounty program and has a CVSS 4.0 score of 5.9 (medium severity).
Potential Impact
Successful exploitation could lead to credential theft of administrators by injecting malicious HTML elements into the login page, potentially compromising administrative access to the GitHub Enterprise Server. The vulnerability requires user interaction and is limited to specific affected versions. There are no known exploits in the wild at this time.
Mitigation Recommendations
This vulnerability has been fixed in GitHub Enterprise Server versions 3.19.6 and 3.20.2. Users should upgrade affected instances to these or later versions to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
CVE-2026-8106: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitHub Enterprise Server
Description
CVE-2026-8106 is a reflected cross-site scripting (XSS) vulnerability in the GitHub Enterprise Server Management Console login page. The issue arises from improper sanitization of the redirect_to query parameter on the /setup/unlock endpoint, allowing injection of malicious HTML elements. An attacker could exploit this by tricking an administrator into clicking a crafted link and entering credentials, potentially leading to credential theft. This vulnerability affects GitHub Enterprise Server versions 3.19.1 through 3.19.5 and 3.20.0 through 3.
CVSS v4.0
Score 5.9medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
A reflected HTML injection vulnerability (CWE-79) exists in the GitHub Enterprise Server Management Console login page due to improper neutralization of the redirect_to query parameter on the /setup/unlock endpoint. This parameter is reflected into an HTML attribute without proper sanitization, enabling an attacker to inject a form element that can capture administrator credentials. Exploitation requires user interaction by an administrator clicking a crafted link and submitting credentials. The vulnerability affects versions 3.19.1 through 3.19.5 and 3.20.0 through 3.20.1 of GitHub Enterprise Server and was addressed in versions 3.19.6 and 3.20.2. The vulnerability was reported through the GitHub Bug Bounty program and has a CVSS 4.0 score of 5.9 (medium severity).
Potential Impact
Successful exploitation could lead to credential theft of administrators by injecting malicious HTML elements into the login page, potentially compromising administrative access to the GitHub Enterprise Server. The vulnerability requires user interaction and is limited to specific affected versions. There are no known exploits in the wild at this time.
Mitigation Recommendations
This vulnerability has been fixed in GitHub Enterprise Server versions 3.19.6 and 3.20.2. Users should upgrade affected instances to these or later versions to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_P
- Date Reserved
- 2026-05-07T14:46:18.902Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69fd095dcbff5d86103c8524
Added to database: 05/07/2026, 21:51:25 UTC
Last enriched: 05/15/2026, 11:01:52 UTC
Last updated: 07/31/2026, 19:23:00 UTC
Views: 153
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