CVE-2026-45781 Details
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.
A vulnerability in the Model Context Protocol (MCP) Registry's handling of Open Container Initiative (OCI) image ownership validation has been identified. Prior to version 1.7.9, the registry's validation process failed to properly check ownership when the upstream OCI registry responded with a HTTP 429 status, indicating that the registry had been rate-limited. This oversight allowed authenticated publishers to falsely claim ownership of OCI images by binding them to their namespace, without actually controlling those images. The vulnerability arises because the label-match check, which serves as the only cross-system ownership proof for OCI packages, is skipped during rate-limit responses. As a result, publishers could exploit this behavior to impersonate authorship of unrelated images, creating a typo-squatting risk on registry search and discovery surfaces.
Users are advised to update to version 1.7.9 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed May 14, 2026CISA-ADP
Assessed May 16, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-636 | Not Failing Securely ('Failing Open') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| modelcontextprotocol MCP Registry | All versions |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 16, 2026 | CVE Modified | CISA-ADP |
| May 14, 2026 | New CVE Received | [email protected] |