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CVE-2026-47427

GitHub MCP Server: Nil Pointer Dereference DoS in completion/complete Handler

Published: Jul 28, 2026Updated: Aug 8, 2026 Sources: CVE List NVDCWE-476
7.5HIGH
NVD MITRE
EPSS Score
0.4%
Top 66.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

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 the server, resulting in a complete denial of service. This issue is fixed in version 1.1.0.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-476

Affected Products

github
commercial·US
mcp serverSaaS
DevTools & CI / source-control
github-mcp-server
DevTools & CI

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Impact
Initial Access
View detailed technique mapping

References

https://github.com/github/github-mcp-server/commit/c88d2ecdd3bb07f7bdd75296e3ee676febf14f58
github.com
https://github.com/github/github-mcp-server/pull/2502
github.com
https://github.com/github/github-mcp-server/releases/tag/v1.1.0
github.com
and 1 more references View all →

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