# CVE-2026-44427: Model Context Protocol Registry open redirect in TrailingSlashMiddleware

Source: https://junglewise.ai/threats/cve-2026-44427-model-context-protocol-registry-open-redirect-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-14. Updated: 2026-05-16  
License: CC BY 4.0 with a link back

CVE-2026-44427 · Severity: medium · CVSS 4 · Published 2026-05-14

The MCP Registry, a component used for managing Model Context Protocol resources, is vulnerable to an open redirect flaw. Attackers can create malicious links that appear to belong to the trusted registry domain but instead redirect users to external, potentially harmful websites. This can be used in phishing campaigns to steal credentials or distribute malware by exploiting the user's trust in the official domain.

Technologies: [github.com/modelcontextprotocol/registry (Go)](https://junglewise.ai/threats/technologies/github-com-modelcontextprotocol-registry), [Model Context Protocol Registry](https://junglewise.ai/threats/technologies/registry). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Model Context Protocol](https://junglewise.ai/threats/vendors/model-context-protocol).

## Quick answers

**Is CVE-2026-44427 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-44427 being exploited in the wild.

**How severe is CVE-2026-44427?** Medium severity, with a CVSS score of 4, published 14 May 2026.

**Which products and versions are affected?** github.com/modelcontextprotocol/registry (Go) >= 1.1.0, < 1.7.5, SEMVER:introduced=1.1.0,fixed=1.7.5; Model Context Protocol Registry 1.1.0 to 1.7.4; Model Context Protocol Registry >= 1.1.0, < 1.7.5.

**Is there a fix for CVE-2026-44427?** Yes. github.com/modelcontextprotocol/registry (Go): upgrade to 1.7.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-44427 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-44427?** Check whether you run github.com/modelcontextprotocol/registry (Go), Model Context Protocol Registry or Model Context Protocol Registry at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/modelcontextprotocol/registry (Go): upgrade to 1.7.5 or later

  ```sh
  go get github.com/modelcontextprotocol/registry@v1.7.5
  ```


## Technical details

The TrailingSlashMiddleware in internal/api/server.go is vulnerable to an open redirect (CWE-601). The middleware strips trailing slashes from request paths and issues a 308 Permanent Redirect to the cleaned path without proper validation. An attacker can craft a URL using a protocol-relative path (e.g., //evil.com/) which, when processed, results in a Location header that browsers interpret as an absolute external URL. This allows remote attackers to redirect users to arbitrary domains. The issue is fixed in version 1.7.5.

## Affected products

- modelcontextprotocol registry >= 1.1.0, < 1.7.5

## Identifiers

- CVE-2026-44427
- GHSA-v8vw-gw5j-w7m6
- GO-2026-5658

## Timeline

- 2026-05-04: disclosed
- 2026-05-08: advisory: GitHub Advisory published
- 2026-05-14: other: NVD published

## References

- [https://api.github.com/users/gujasec](https://api.github.com/users/gujasec)
- [https://github.com/gujasec](https://github.com/gujasec)
- [https://api.github.com/users/gujasec/gists%7B/gist_id%7D](https://api.github.com/users/gujasec/gists%7B/gist_id%7D)
- [https://api.github.com/users/gujasec/repos](https://api.github.com/users/gujasec/repos)
- [https://avatars.githubusercontent.com/u/43931578?v=4](https://avatars.githubusercontent.com/u/43931578?v=4)
- [https://api.github.com/users/gujasec/events%7B/privacy%7D](https://api.github.com/users/gujasec/events%7B/privacy%7D)

## Related threats

- [Model Context Protocol Registry OIDC token replay via shared audience](https://junglewise.ai/threats/cve-2026-44428-model-context-protocol-registry-oidc-token-replay-via-shared)
- [Model Context Protocol Registry ownership bypass in OCI validator](https://junglewise.ai/threats/cve-2026-45781-model-context-protocol-registry-ownership-bypass-in-oci-validator)
- [Model Context Protocol Registry SSRF via IPv6 Filter Bypass](https://junglewise.ai/threats/cve-2026-44430-model-context-protocol-registry-ssrf-via-ipv6-filter-bypass)
- [MCP Registry stored XSS in catalogue UI via websiteUrl](https://junglewise.ai/threats/cve-2026-44429-mcp-registry-stored-xss-in-catalogue-ui-via-websiteurl)