mcp has 13 CVEs on record between 2025 and 2026. Disclosures have slowed: 3 in the last 90 days after 8 in the 90 before. The busiest recent month was July 2026 with 8. The median CVSS is 6.8 (medium). None have a confirmed exploitation report. The most common weakness class is CWE-770 (4). Most affected products: mcp (12), mcp/sdk (1).
CVEs per month
Last 12 months, by publish date
- Exploited share
- 0% vs 1% corpus
- Median CVSS
- 6.8
- Publish → KEV
- —
- Last 90 days
- 3 prev 8
Weakness classes
Products
- mcp 12
- mcp/sdk 1
Worst active — by depth score
CVE-2025-53366HighMCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS43CVE-2026-52870High· 7.6MCP Python SDK: Experimental task handlers allow any client to access and cancel other clients' tasks42CVE-2026-53965HighThe MCP PHP SDK (Composer package mcp/sdk) is the official Model Context Protocol SDK for PHP41CVE-2026-67432High· 7.5MCP Ruby SDK: Unbounded JSON-RPC request body causes uncontrolled memory allocation in StreamableHTTPTransport41CVE-2026-67431HighMCP Ruby SDK: Ruby SSE Session Poisoning41
mcp vulnerabilities
CVEs affecting mcp, newest first. Open any entry for full detail, references, and exploit status.
13 CVEsRSS
CVE-2026-116684Medium· 6.8Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server
Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server
CVE-2026-116685Medium· 5.9Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies
Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies
CVE-2026-53965HighThe MCP PHP SDK (Composer package mcp/sdk) is the official Model Context Protocol SDK for PHP
The MCP PHP SDK (Composer package mcp/sdk) is the official Model Context Protocol SDK for PHP. In versions 0.5.0 through 0.7.0, the HTTP client transport reads a Server-Sent Events response stream incrementally and appends each chunk to …
CVE-2026-63118MediumMCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection
MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection
CVE-2026-63119Medium· 6.2MCP Ruby SDK: Unbounded line buffer in stdio transports leads to memory exhaustion (DoS)
MCP Ruby SDK: Unbounded line buffer in stdio transports leads to memory exhaustion (DoS)
CVE-2026-67430Medium· 5.3MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood
MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood
CVE-2026-67432High· 7.5MCP Ruby SDK: Unbounded JSON-RPC request body causes uncontrolled memory allocation in StreamableHTTPTransport
MCP Ruby SDK: Unbounded JSON-RPC request body causes uncontrolled memory allocation in StreamableHTTPTransport
CVE-2026-67431HighMCP Ruby SDK: Ruby SSE Session Poisoning
MCP Ruby SDK: Ruby SSE Session Poisoning
CVE-2026-52869High· 7.1MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal
MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal
CVE-2026-59950HighMCP Python SDK: WebSocket server transport does not support Host/Origin validation
MCP Python SDK: WebSocket server transport does not support Host/Origin validation
CVE-2026-52870High· 7.6MCP Python SDK: Experimental task handlers allow any client to access and cancel other clients' tasks
MCP Python SDK: Experimental task handlers allow any client to access and cancel other clients' tasks
CVE-2025-53365HighMCP Python SDK has Unhandled Exception in Streamable HTTP Transport, Leading to Denial of Service
MCP Python SDK has Unhandled Exception in Streamable HTTP Transport, Leading to Denial of Service
CVE-2025-53366HighMCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS
MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS