Is CVE-2026-44429 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-44429 being exploited in the wild.

How severe is CVE-2026-44429?

Medium severity, with a CVSS score of 5.4, published 14 May 2026.

Which products and versions are affected?

github.com/modelcontextprotocol/registry (Go) < 1.7.7, SEMVER:introduced=0,fixed=1.7.7; Model Context Protocol Registry < 1.7.7; Model Context Protocol Registry < 1.7.7.

Is there a fix for CVE-2026-44429?

Yes. github.com/modelcontextprotocol/registry (Go): upgrade to 1.7.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-44429 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-44429?

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.

CVE-2026-44429: MCP Registry stored XSS in catalogue UI via websiteUrl

Q: Is there a fix for CVE-2026-44429?

Yes. github.com/modelcontextprotocol/registry (Go): upgrade to 1.7.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-44429 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-44429?

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.

CVE-2026-44429 · Severity: medium · CVSS 5.4 · Published 2026-05-14

The Model Context Protocol (MCP) Registry is a directory for AI-related server components. A vulnerability in the registry's web interface allows malicious publishers to inject malicious scripts into the catalogue. If a user views a poisoned entry, the attacker could steal authentication tokens, redirect the user to malicious sites, or perform actions on the user's behalf within the registry.

Technologies: github.com/modelcontextprotocol/registry (Go), Model Context Protocol Registry. Vendors: Go, Model Context Protocol.

Quick answers

Is CVE-2026-44429 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-44429 being exploited in the wild.
How severe is CVE-2026-44429?: Medium severity, with a CVSS score of 5.4, published 14 May 2026.
Which products and versions are affected?: github.com/modelcontextprotocol/registry (Go) < 1.7.7, SEMVER:introduced=0,fixed=1.7.7; Model Context Protocol Registry < 1.7.7; Model Context Protocol Registry < 1.7.7.
Is there a fix for CVE-2026-44429?: Yes. github.com/modelcontextprotocol/registry (Go): upgrade to 1.7.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-44429 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-44429?: 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 1.7.7 or later
```
go get github.com/modelcontextprotocol/registry@v1.7.7
```

Technical details

A stored cross-site scripting (XSS) vulnerability exists in the MCP Registry catalogue UI due to improper output encoding of the `websiteUrl` field. While the application uses a homegrown `escapeHtml` helper, this helper only sanitizes characters for text content (like `<` and `&`) and fails to escape double quotes (`"`). An attacker with publishing privileges can provide a URL containing a double quote to break out of the `href` attribute in the `ui_index.html` template. This allows the injection of arbitrary HTML attributes, such as `onmouseover`, which execute JavaScript when a user interacts with the malicious entry. The existing Content Security Policy (CSP) fails to mitigate this because it includes `'unsafe-inline'`. The issue is fixed in version 1.7.7 by improving validation and encoding.

Affected products

modelcontextprotocol registry < 1.7.7

Identifiers

CVE-2026-44429
GHSA-rqv2-m695-f8j4
GO-2026-5637

Timeline

2026-05-04: disclosed: Vulnerability reported to vendor
2026-05-08: advisory: GitHub Advisory published
2026-05-08: patched: Fix released in version 1.7.7

References

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