GitHub Enterprise Server up to 3.21.1 clickjacking

Summaryinfo

A vulnerability categorized as problematic has been discovered in GitHub Enterprise Server up to 3.17.16/3.18.10/3.19.7/3.20.3/3.21.1. This affects an unknown function. Executing a manipulation can lead to clickjacking. This vulnerability is registered as CVE-2026-9106. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in GitHub Enterprise Server up to 3.17.16/3.18.10/3.19.7/3.20.3/3.21.1. It has been declared as problematic. This vulnerability affects an unknown functionality. The manipulation with an unknown input leads to a clickjacking vulnerability. The CWE definition for the vulnerability is CWE-451. The user interface (UI) does not properly represent critical information to the user, allowing the information - or its source - to be obscured or spoofed. This is often a component in phishing attacks. As an impact it is known to affect integrity. CVE summarizes:

A UI misrepresentation vulnerability was identified in GitHub Enterprise Server that allowed an OAuth application to gain unintended access to an organization's runner management. An attacker could exploit this by creating an OAuth application requesting the manage_runners:org scope and directing a victim user to authorize it, as the scope was not displayed on the authorization consent screen. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.21.2, 3.20.4, 3.19.8, 3.18.11, 3.17.17. This vulnerability was reported via the GitHub Bug Bounty program.

The advisory is shared for download at docs.github.com. This vulnerability was named CVE-2026-9106 since 05/20/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1566.003.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-2164). Once again VulDB remains the best source for vulnerability data.

Affected

• Microsoft GitHub Enterprise

Productinfo

Type

• Bug Tracking Software

Vendor

• GitHub

Name

• Enterprise Server

Version

• 3.17.0
• 3.17.1
• 3.17.2
• 3.17.3
• 3.17.4
• 3.17.5
• 3.17.6
• 3.17.7
• 3.17.8
• 3.17.9
• 3.17.10
• 3.17.11
• 3.17.12
• 3.17.13
• 3.17.14
• 3.17.15
• 3.17.16
• 3.18.0
• 3.18.1
• 3.18.2
• 3.18.3
• 3.18.4
• 3.18.5
• 3.18.6
• 3.18.7
• 3.18.8
• 3.18.9
• 3.18.10
• 3.19.0
• 3.19.1
• 3.19.2
• 3.19.3
• 3.19.4
• 3.19.5
• 3.19.6
• 3.19.7
• 3.20.0
• 3.20.1
• 3.20.2
• 3.20.3
• 3.21.0
• 3.21.1

License

• open-source

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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