Improper Token Validation in MCP Registry Affecting Multiple Deployments
CVE-2026-44428

2.1LOW

Key Information:

Vendor

Modelcontextprotocol

Status
Registry
Vendor
CVE Published:
14 May 2026

What is CVE-2026-44428?

The MCP Registry, designed to facilitate interactions between MCP clients and servers, exhibits a significant flaw in its client-side and server-side validation of GitHub OIDC tokens. Before version 1.7.6, the implementation utilized a global audience string for authorization, leading to a lack of specificity for individual registry instances. This flaw allowed tokens issued for one deployment to be misused across others sharing the same audience identifier. The vulnerability was addressed in version 1.7.6, ensuring tokens are validated against the specific registry instance being accessed.

Affected Version(s)

registry < 1.7.6

References

https://github.com/modelcontextprotocol/registry/security...
x_refsource_CONFIRM

CVSS V4

Score:
2.1
Severity:
LOW
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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