NVD / CVE Program· CNA GitHub_P

CVE-2026-6736: Authentication bypass vulnerability in GitHub Enterprise Server allowed creation of local user accounts bypassing the configured external identity provider

Noroxi assessment

Priority: Monitor (action score 25/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.26% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: GitHub Enterprise Server 3.16.18, 3.17.15, 3.18.9.

Low priority for now. Upgrade to GitHub Enterprise Server 3.16.18, 3.17.15, 3.18.9 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 6.3 · v4.0—No exploit Fix available

Published: May 7, 2026
Updated: Oct 26, 2026
EPSS: 0.2% · 18th percentile
CWE: CWE-306

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 25 / 40 · 6.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_P: 6.3; NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
github	enterprise server	cpe:2.3:a:github:enterprise_server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

github enterprise serverbefore 3.16.18
github enterprise server3.17.0 and later · before 3.17.15
github enterprise server3.18.0 and later · before 3.18.9
github enterprise server3.19.0 and later · before 3.19.6
github enterprise server3.20.0 and later · before 3.20.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_P). Independent of NVD's CPE analysis and usually ahead of it.

GitHub Enterprise Server
- 3.16.0 and later · up to and including 3.16.17affected · semverfixed in 3.16.18
- 3.17.0 and later · up to and including 3.17.14affected · semverfixed in 3.17.15
- 3.18.0 and later · up to and including 3.18.8affected · semverfixed in 3.18.9
- 3.19.0 and later · up to and including 3.19.5affected · semverfixed in 3.19.6
- 3.20.0 and later · up to and including 3.20.1affected · semverfixed in 3.20.2

Same product

github: all records

Other highest-scoring records for the same primary product.

CVE-2024-0200Unsafe Reflection in Github Enterprise Server leading to Command Injection
61This week
CVE-2024-0507Privilege Escalation by Code Injection in the Management Console in GitHub Enterprise Server
55Plan
CVE-2026-3854Remote code execution via git push option injection in GitHub Enterprise Server
46Plan

Published before and after this one in the same product

← EarlierCVE-2026-5845Apr 21, 2026 · Improper authorization fallback allows scoped user-to-server token installation escape in GitHub Enterprise Server
28Monitor
← EarlierCVE-2026-5921Apr 21, 2026 · Server-Side Request Forgery in GitHub Enterprise Server allowed extraction of sensitive environment variables via timing side-channel attack
35Monitor
Later →CVE-2026-7541May 7, 2026 · Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via unauthenticated API endpoint
25Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
GitHub Enterprise Server	3.16.18	Vendor (CNA)
GitHub Enterprise Server	3.17.15	Vendor (CNA)
GitHub Enterprise Server	3.18.9	Vendor (CNA)
GitHub Enterprise Server	3.19.6	Vendor (CNA)
GitHub Enterprise Server	3.20.2	Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2026-385458 days apartRemote code execution via git push option injection in GitHub Enterprise Server
46Plan
CVE-2026-1534371 days apartPath traversal vulnerability in GitHub Enterprise Server allowed writing files to arbitrary repository paths, including GitHub Actions workflow files, via unche
34Monitor
CVE-2026-226658 days apartImproper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed cross-site scripting via task list content and enabled ar
29Monitor
CVE-2026-1058554 days apartStored cross-site scripting vulnerability in GitHub Enterprise Server allowed arbitrary JavaScript execution via crafted Discussion titles in the Q&A category
25Monitor

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS 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

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:10 PM UTC

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References

docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records