CVE-2026-45781 — LOW (3.5) — White Hats Nepal

Vulnerability Description

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.9, OCI ownership validation skips label-match check when upstream OCI registry returns HTTP 429, letting any authenticated publisher bind their io.github.<user>/* namespace to OCI images they do not control. internal/validators/registries/oci.go:104-119 fails open on http.StatusTooManyRequests: when the registry's anonymous fetch to the upstream OCI registry is rate-limited, ValidateOCI returns nil and the publish is accepted without ever running the io.modelcontextprotocol.server.name label-match check at lines 122-141. That label check is the only cross-system ownership proof the registry applies to OCI packages — every other registry type (NPM, PyPI, NuGet, MCPB) treats a non-200 upstream response as a hard error. This vulnerability is fixed in 1.7.9.

CVSS Score

3.5

LOW

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-636

References

FAQ

What is CVE-2026-45781?

CVE-2026-45781 is a vulnerability with a CVSS score of 3.5 (LOW). The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.9, OCI ownership validation skips label-match check when upstream OCI registry returns...

How severe is CVE-2026-45781?

CVE-2026-45781 has been rated LOW with a CVSS base score of 3.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-45781?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.