CVE-2026-47427: GitHub MCP Server is GitHub's official MCP Server

Q: How do I fix CVE-2026-47427?

mcp server: upgrade to 1.1.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-47427 being exploited?

CVE-2026-47427 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-47427 affect?

CVE-2026-47427 affects mcp server. Severity is high (CVSS 7.5). GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empt

Q: How urgent is CVE-2026-47427?

Priority 50/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-47427 is a high-severity flaw (CVSS 7.5) affecting mcp server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empty ref field triggers a nil pointer dereference and a Go runtime panic; because the crash occurs before any authentication or token validation, any unauthenticated client able to send JSON-RPC messages can crash

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 45%)
CISA exploited list	No
Weakness	CWE-476
Published	2026-07-28
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: github

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-28 16:18 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

github mcp server UPGRADE

Affected: < 1.1.0

Fixed in: 1.1.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mcp-server || rpm -q mcp-server || mcp-server --version

2. UPGRADE to 1.1.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mcp-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mcp-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Go · github.com/github/github-mcp-server · FIXED · 1.1.0 · vulnerable: < 1.1.0 · source

go get github.com/github/github-mcp-server@v1.1.0 go list -m github.com/github/github-mcp-server

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-47427?

mcp server: upgrade to 1.1.0. Exact commands for each OS are on this page.

Is CVE-2026-47427 being exploited?

CVE-2026-47427 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-47427 affect?

CVE-2026-47427 affects mcp server. Severity is high (CVSS 7.5). GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empt

How urgent is CVE-2026-47427?

Priority 50/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

GitHub vulnerabilities

References

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