CVE-2026-6736 : faille moyenne github enterprise server (CVSS 6.5)

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.

Sévérité

Moyenne (CVSS 6.5)

Vecteur CVSS

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploitation active

Non signalée par la CISA

Publication

7 mai 2026

Dernière mise à jour

17 juin 2026

• github enterprise server

• Fiche CVE-2026-6736 sur le NVD (NIST)
• docs.github.com/en/[email protected]/admin/release-notes
• docs.github.com/en/[email protected]/admin/release-notes
• docs.github.com/en/[email protected]/admin/release-notes
• docs.github.com/en/[email protected]/admin/release-notes
• docs.github.com/en/[email protected]/admin/release-notes