CVE-2026-6736Authentication bypass vulnerability in GitHub Enterprise Server allowed creation of local user accounts bypassing the configured external identity provider
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 6.3 MEDIUM (v4.0, CNA)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
- Weakness (CWE)
- CWE-306
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_P
- NVD analysis
- Analyzed
- Record last updated
- May 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
GitHub Enterprise Server github:enterprise_server (from the name) | from 3.16.0 through 3.16.17; fixed at 3.16.18; from 3.17.0 through 3.17.14; fixed at 3.17.15; from 3.18.0 through 3.18.8; fixed at 3.18.9; from 3.19.0 through 3.19.5; fixed at 3.19.6; from 3.20.0 through 3.20.1; fixed at 3.20.2 | CNA record |
github enterprise_server github:enterprise_server | before 3.16.18; from 3.17.0 before 3.17.15; from 3.18.0 before 3.18.9; from 3.19.0 before 3.19.6; from 3.20.0 before 3.20.2 | NVD |
References
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18release-notes, vendor-advisory
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15release-notes, vendor-advisory
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9release-notes, vendor-advisory
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6release-notes, vendor-advisory
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2release-notes, vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.