CVE-2026-52869
7.1 · HIGHOverview
CVE-2026-52869 is a high-severity vulnerability affecting lfprojects mcp_python_sdk. It was published on July 15, 2026 and has a CVSS 3.1 base score of 7.1 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.1, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to 1.27.2, the SSE and stateful Streamable HTTP transports mcp.server.sse.SseServerTransport and mcp.server.streamable_http_manager.StreamableHTTPSessionManager route requests to existing sessions using only the session_id query parameter or Mcp-Session-Id header without verifying the authenticated principal that created the session, allowing a different bearer-token-authenticated client with a known session ID to inject JSON-RPC messages into that session. This issue is fixed in version 1.27.2.
Remediation
Check the references section for vendor advisories and patches from lfprojects. Update mcp_python_sdk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| lfprojects | mcp_python_sdk | >= 0, < 1.27.2 | Affected |
References
Frequently Asked Questions
What is CVE-2026-52869?
CVE-2026-52869 is a high-severity vulnerability affecting lfprojects mcp_python_sdk. It was published on July 15, 2026 and has a CVSS 3.1 base score of 7.1 (HIGH).
How severe is CVE-2026-52869?
This vulnerability has a CVSS 3.1 base score of 7.1, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-52869?
Check the references section for vendor advisories and patches from lfprojects. Update mcp_python_sdk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-52869?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-52869 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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