CVE-2026-6736
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 6.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-306 · Missing authentication
- Record status
- Analyzed
Affected
- GitHub Enterprise Server < 3.16.18
- GitHub Enterprise Server < 3.17.15
- GitHub Enterprise Server < 3.18.9
- GitHub Enterprise Server < 3.19.6
- GitHub Enterprise Server < 3.20.2
Attack profile CVSS 4.0 · 6.3
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- None
- User interaction
- None
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Raw vector
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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-6736.md and follow it. Check whether this project is affected by CVE-2026-6736. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2
References
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2