# rmcp (crates.io) vulnerabilities

4 known vulnerabilities (3 high, 1 medium), with the versions each affects and the releases that fix them.

## At a glance

- Latest release: 3.9.0 (Nov 5, 2026): no advisory affects it
- Newest unaffected release: 3.9.0 (Nov 5, 2026), the latest release
- Weekly downloads: 1.9M
- Dependents: 0
- Releases: 72 since 0.1.0 (Mar 16, 2025)
- Registry: https://crates.io/crates/rmcp
- Releases read: Nov 8, 2026

## Version timeline

Affected versions per advisory, in version order:

- CVE-2026-64684: 0.1.0 to 2.0.0 (2.1.0 is outside it)
- CVE-2026-63127: 0.1.0 to 1.8.0 (2.0.0 is outside it)
- CVE-2026-63128: 0.1.0 to 1.8.0 (2.0.0 is outside it)
- CVE-2026-42559: 0.1.0 to 1.3.0 (1.4.0 is outside it)

## Advisories (4)

### [CVE-2026-64684](https://cve.now/CVE-2026-64684): RMCP: Custom HTTP headers leak to cross-origin redirect targets

- Severity: Medium 6.8
- Published: Sep 16, 2026
- Affected: fixed in 2.1.0.
- Fixed in 2.1.0 (released Jul 2, 2026, 76 days before disclosure).
- The latest release, 3.9.0, is not affected.

### [CVE-2026-63127](https://cve.now/CVE-2026-63127): RMCP: Missing Resource Field Validation in OAuth Protected Resource Metadata Discovery

- Severity: High 8.2
- Published: Sep 16, 2026
- Affected: fixed in 2.0.0.
- Fixed in 2.0.0 (released Jun 29, 2026, 79 days before disclosure).
- The latest release, 3.9.0, is not affected.

### [CVE-2026-63128](https://cve.now/CVE-2026-63128): RMCP: Unauthenticated permanent session-table leak in rmcp Streamable HTTP server transport leads to remote denial-of-service

- Severity: High 7.5
- Published: Sep 16, 2026
- Affected: fixed in 2.0.0.
- Fixed in 2.0.0 (released Jun 29, 2026, 79 days before disclosure).
- The latest release, 3.9.0, is not affected.

### [CVE-2026-42559](https://cve.now/CVE-2026-42559): RMCP: DNS rebinding vulnerability in rmcp Streamable HTTP server transport

- Severity: High 8.8
- Published: May 14, 2026
- Affected: fixed in 1.4.0; fixed in 1.4.0.
- Fixed in 1.4.0 (released Apr 10, 2026, 34 days before disclosure).
- The latest release, 3.9.0, is not affected.

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