NIXPKGS-2026-2300

GitHub issue published 3 hours ago

MCP Python SDK: WebSocket server transport does not support Host/Origin validation

Permalink CVE-2026-59950

7.6 HIGH

CVSS version (CVSS): 4.0
Attack Vector (AV): Network (N)
Attack Complexity (AC): Low (L)
Attack Requirement (AT): Present (P)
Privileges Required (PR): None (N)
User Interaction (UI): Passive (P)
Vulnerable System Impact Confidentiality (VC): High (H)
Vulnerable System Impact Integrity (VI): High (H)
Vulnerable System Impact Availability (VA): None (N)
Subsequent System Impact Confidentiality (SC): None (N)
Subsequent System Impact Integrity (SI): None (N)
Subsequent System Impact Availability (SA): None (N)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): Low (L)
Modified Attack Requirement (MAT): Present (P)
Modified Privileges Required (MPR): None (N)
Modified User Interaction (MUI): Passive (P)
Modified Vulnerable System Impact Confidentiality (MVC): High (H)
Modified Vulnerable System Impact Integrity (MVI): High (H)
Modified Vulnerable System Impact Availability (MVA): None (N)
Modified Subsequent System Impact Confidentiality (MSC): Negligible (N)
Modified Subsequent System Impact Integrity (MSI): Negligible (N)
Modified Subsequent System Impact Availability (MSA): Negligible (N)
Safety (S): Not Defined (X)
Automatable (AU): Not Defined (X)
Recovery (R): Not Defined (X)
Value Density (V): Not Defined (X)
Vulnerability Response Effort (RE): Not Defined (X)
Provider Urgency (U): Not Defined (X)
Confidentiality Req. (CR): Not Defined (X)
Integrity Req. (IR): Not Defined (X)
Availability Req. (AR): Not Defined (X)
Exploit Maturity (E): Not Defined (X)

updated 3 hours ago by @erictapen Activity log

Created suggestion 1 week, 1 day ago
@erictapen ignored
18 packages
- python314Packages.aliyun-python-sdk-config
- python313Packages.aliyun-python-sdk-config
- python314Packages.aliyun-python-sdk-alimt
- python313Packages.aliyun-python-sdk-alimt
- python314Packages.aliyun-python-sdk-dbfs
- python314Packages.aliyun-python-sdk-core
- python313Packages.aliyun-python-sdk-dbfs
- python313Packages.aliyun-python-sdk-core
- python314Packages.aliyun-python-sdk-sts
- python314Packages.aliyun-python-sdk-kms
- python314Packages.aliyun-python-sdk-iot
- python314Packages.aliyun-python-sdk-cdn
- python313Packages.aliyun-python-sdk-sts
- python313Packages.aliyun-python-sdk-kms
- python313Packages.aliyun-python-sdk-iot
- python313Packages.aliyun-python-sdk-cdn
- python314Packages.bce-python-sdk
- python313Packages.bce-python-sdk
3 hours ago
@erictapen accepted 3 hours ago
@erictapen published on GitHub 3 hours ago

MCP Python SDK: WebSocket server transport does not support Host/Origin validation

The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to 1.28.1, the deprecated mcp.server.websocket.websocket_server transport accepted WebSocket handshakes without applying Host or Origin header validation, leaving no SDK-level way to restrict which origins could connect to applications that exposed that transport. This issue is fixed in version 1.28.1.