CVE-2026-6736
published 2026-05-07CVE-2026-6736: An authentication bypass vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to create a local user account…
PriorityP345medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
EPSS
0.27%
17.9th percentile
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.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github | enterprise_server | < 3.16.18 | 3.16.18 |
| github | enterprise_server | 3.16.0 – 3.16.17 | — |
| github | enterprise_server | >= 3.17.0 < 3.17.15 | 3.17.15 |
| github | enterprise_server | 3.17.0 – 3.17.14 | — |
| github | enterprise_server | >= 3.18.0 < 3.18.9 | 3.18.9 |
| github | enterprise_server | 3.18.0 – 3.18.8 | — |
| github | enterprise_server | >= 3.19.0 < 3.19.6 | 3.19.6 |
| github | enterprise_server | 3.19.0 – 3.19.5 | — |
| github | enterprise_server | >= 3.20.0 < 3.20.2 | 3.20.2 |
| github | enterprise_server | 3.20.0 – 3.20.1 | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
nvdv4.06.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2
2026-05-07
Published