An authentication bypass vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to create a local user account, bypassing the configured external identity provider. When external authentication was enabled, the signup endpoint did not properly enforce the authentication restriction, allowing account creation and session establishment without identity provider validation. The created account was limited to the default base permissions configured on the instance. Exploitation required network access to a GHES instance configured with an external authentication provider. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.2, 3.19.6, 3.18.9, 3.17.15, and 3.16.18.
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Thu, 07 May 2026 23:15:00 +0000
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Github
Github enterprise Server |
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Github
Github enterprise Server |
Thu, 07 May 2026 21:45:00 +0000
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| Title | Missing Authentication for Critical Function vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to create a local user account bypassing the external identity provider | Authentication bypass vulnerability in GitHub Enterprise Server allowed creation of local user accounts bypassing the configured external identity provider |
Thu, 07 May 2026 21:30:00 +0000
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| Description | An authentication bypass vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to create a local user account, bypassing the configured external identity provider. When external authentication was enabled, the signup endpoint did not properly enforce the authentication restriction, allowing account creation and session establishment without identity provider validation. The created account was limited to the default base permissions configured on the instance. Exploitation required network access to a GHES instance configured with an external authentication provider. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.2, 3.19.6, 3.18.9, 3.17.15, and 3.16.18. | |
| Title | Missing Authentication for Critical Function vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to create a local user account bypassing the external identity provider | |
| Weaknesses | CWE-306 | |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_P
Published: 2026-05-07T21:14:33.490Z
Updated: 2026-05-07T21:27:45.553Z
Reserved: 2026-04-21T02:53:28.704Z
Link: CVE-2026-6736
No data.
Status : Received
Published: 2026-05-07T22:16:36.753
Modified: 2026-05-07T22:16:36.753
Link: CVE-2026-6736
No data.
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