CVE-2026-47427Public exploitNetwork attack vector

Unauthenticated process crash via nil ref dereference

Published Jul 28, 2026 · Updated Jul 28, 2026

Nil pointer dereference in GitHub MCP Server before 1.1.0 allows remote attackers to crash the server via a malformed completion request. CompletionsHandler in pkg/github/server.go dereferences params.Ref without a nil check, causing a Go runtime panic when ref is absent or empty. Reachability requires only the MCP initialization handshake and JSON-RPC message access; the unrecoverable panic terminates the process before authentication or token validation.

CVSS severity7.5
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Nil pointer dereference in GitHub MCP Server before 1.1.0 allows remote attackers to crash the server via a malformed completion request. CompletionsHandler in pkg/github/server.go dereferences params.Ref without a nil check, causing a Go runtime panic when ref is absent or empty. Reachability requires only the MCP initialization handshake and JSON-RPC message access; the unrecoverable panic terminates the process before authentication or token validation.

The record

CVE
CVE-2026-47427
Published
Jul 28, 2026
Updated
Jul 28, 2026
Vendor
Twitter
Product
GitHub MCP Server
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Twitter · GitHub MCP Serverversion=< 1.1.0

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo