CVE catalog
CVE-2026-6736
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 pr
- Severity
- Medium · CVSS 6.3
CVSS: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 - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.27% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | enterprise_server | Not reported | 3.16.18 | fixed |
| Cpe | enterprise_server | Not reported | 3.17.15 | fixed |
| Cpe | enterprise_server | Not reported | 3.18.9 | fixed |
| Cpe | enterprise_server | Not reported | 3.19.6 | fixed |
| Cpe | enterprise_server | Not reported | 3.20.2 | fixed |
| Cpe | enterprise_server | Not reported | 3.20.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Cpe | enterprise_server | cpe | Not reported | 3.16.18 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.17.15 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.18.9 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.19.6 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.20.2 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.20.2 | Not reported | NVD-CVE-2026-6736 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed:
References
- [https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18]
- [https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15]
- [https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9]
- [https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6]
- [https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-6736]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1432.json]
[CERT-Bund public advisories] · [FIRST EPSS] · [National Vulnerability Database (NVD)]