CVE-2026-6736
Authentication bypass vulnerability in GitHub Enterprise Server allowed creation of local user accounts bypassing the configured external identity provider
- Published
- Updated
- Reserved
- Assigned by
- GitHub_P
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_PCNA (assigner) | 4.0 | Medium6.3 | 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 |
| NVDNVD · Analyzed | 4.0 | Medium6.3 | 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 |
- EPSS (exploitation in 30 days)
- 0.27% · top 81% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.
Weakness
Affected products
- affected 3.16.0 – ≤ 3.16.17
- affected 3.17.0 – ≤ 3.17.14
- affected 3.18.0 – ≤ 3.18.8
- affected 3.19.0 – ≤ 3.19.5
- affected 3.20.0 – ≤ 3.20.1
References (5)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18 (opens in a new tab)release-notes
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15 (opens in a new tab)release-notes
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9 (opens in a new tab)release-notes
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6 (opens in a new tab)release-notes
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2 (opens in a new tab)release-notes
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-6736)Record last updated .