Access Control Flaw in GitHub MCP Server Affects User Privacy
CVE-2026-48529

6MEDIUM

Key Information:

Vendor

Github
Status
Github-mcp-server
Vendor
CVE Published:
26 June 2026

What is CVE-2026-48529?

The GitHub MCP Server contains an access control vulnerability where a process-global singleton is incorrectly initialized with the credentials of the first authenticated user. This implementation flaw means that subsequent requests from other users access the shared singleton, causing sensitive GraphQL queries to execute under the initial user's credentials rather than the latest user's tokens. This leads to unauthorized access to resources and could potentially expose user-related data. The flaw affects versions 0.22.0 through 1.1.1 and has been addressed in version 1.1.2.

Affected Version(s)

github-mcp-server >= 0.22.0, < 1.1.2

References

https://github.com/github/github-mcp-server/security/advi...
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CVSS V3.1

Score:
6
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.