Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-45781— MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims

Quick assessment

Affected
modelcontextprotocol registry
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MCP Registry是Model Context Protocol开源的一个MCP服务器应用商店。 MCP Registry 1.7.9之前版本存在安全漏洞，该漏洞源于OCI所有权验证在HTTP 429时跳过标签匹配检查，可能导致命名空间绑定到未控制的镜像。

CVSS 3.5 · Low EPSS 0.25% · P15

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

VendorProduct Version RangeStatus
modelcontextprotocol registry < 1.7.9 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-45781

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims
Source: CVE Program / CVE List V5
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: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
未能安全地进行程序失效(Failing Open)
Source: CVE Program / CVE List V5
Vulnerability Title
MCP Registry 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
MCP Registry是Model Context Protocol开源的一个MCP服务器应用商店。 MCP Registry 1.7.9之前版本存在安全漏洞，该漏洞源于OCI所有权验证在HTTP 429时跳过标签匹配检查，可能导致命名空间绑定到未控制的镜像。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China 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
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-45781

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-45781 (1)

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 product: registry
Same vendor: modelcontextprotocol
Same weakness: CWE-636

V. Comments for CVE-2026-45781

No comments yet

Leave a comment