modelcontextprotocol registry up to 1.7.8 OCI Image failing open

Summaryinfo

A vulnerability, which was classified as problematic, has been found in modelcontextprotocol registry up to 1.7.8. The affected element is an unknown function of the component OCI Image Handler. Performing a manipulation results in failing open. This vulnerability is cataloged as CVE-2026-45781. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in modelcontextprotocol registry up to 1.7.8. It has been classified as problematic. This affects an unknown functionality of the component OCI Image Handler. The manipulation with an unknown input leads to a failing open vulnerability. CWE is classifying the issue as CWE-636. When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions. This is going to have an impact on integrity. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-45781 since 05/13/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Neither technical details nor an exploit are publicly available.

Upgrading to version 1.7.9 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-30489). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• modelcontextprotocol

Name

• registry

Version

• 1.7.0
• 1.7.1
• 1.7.2
• 1.7.3
• 1.7.4
• 1.7.5
• 1.7.6
• 1.7.7
• 1.7.8

Website

• Product: https://github.com/modelcontextprotocol/registry/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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