CVE-2026-45781— MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims
Possible ATT&CK Techniques 1AI
T1190 · Exploit Public-Facing ApplicationAffected Version Matrix 1
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| modelcontextprotocol | registry | < 1.7.9 | affected |
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I. Basic Information for CVE-2026-45781
Vulnerability Information
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Vulnerability Title
MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims
Source: NVD (National Vulnerability Database)
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.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
未能安全地进行程序失效(Failing Open)
Source: NVD (National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| modelcontextprotocol | registry | < 1.7.9 | - |
II. Public POCs for CVE-2026-45781
| # | POC Description | Source Link | Shenlong Link |
|---|
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Same Patch Batch · modelcontextprotocol · 2026-05-14 · 6 CVEs total
| CVE-2026-42559 | 8.8 HIGH | RMCP: DNS rebinding vulnerability in rmcp Streamable HTTP server transport |
| CVE-2026-44429 | MCP Registry: Stored XSS in catalogue UI via attribute-quote breakout in publisher-control | |
| CVE-2026-44430 | MCP Registry: Unauthenticated SSRF: HTTP namespace verification dials 6to4 / NAT64 / site- | |
| CVE-2026-44427 | MCP Registry: Open Redirect | |
| CVE-2026-44428 | MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audi |
IV. Related Vulnerabilities
Same vendor: modelcontextprotocol
- CVE-2026-44428
MCP Registry: GitHub OIDC tokens replayable across registry - CVE-2026-44427
MCP Registry: Open Redirect - CVE-2026-44429
MCP Registry: Stored XSS in catalogue UI via attribute-quote - CVE-2026-44430
MCP Registry: Unauthenticated SSRF: HTTP namespace verificat - CVE-2026-42559
RMCP: DNS rebinding vulnerability in rmcp Streamable HTTP se
Same weakness: CWE-636
- CVE-2026-42423
OpenClaw < 2026.4.8 - strictInlineEval Approval Boundary Byp - CVE-2026-41377
OpenClaw < 2026.3.31 - Fail-Open Security Scan Bypass in Plu - CVE-2026-41334
OpenClaw < 2026.3.31 - Decompression Bomb Denial of Service - CVE-2026-40525
OpenViking < 0.3.9 Authentication Bypass via VikingBot OpenA - CVE-2026-35205
Helm's plugin verification fails open when .prov is missing,
V. Comments for CVE-2026-45781
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