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High 8.1Published Jul 15, 2026

CVE-2026-59950The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP).

Updated under an hour ago ()

Does this affect you?

It affects lfprojects mcp_python_sdk. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
8.1 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Weakness (CWE)
CWE-346, CWE-1385
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Jul 17, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
lfprojects mcp_python_sdk
lfprojects:mcp_python_sdk
before 1.28.1
NVD

References

  • patch
  • issue-tracking, patch
  • release-notes
  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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