CVE-2026-53965

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 an in-memory buffer with no upper bound. The buffer is only...

CVE-2026-53965 MCP PHP SDK: Unbounded SSE buffer in HttpTransport enables client-side denial of service

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 an in-memory buffer with no upper bound. The buffer is only...

PT-2026-80737

Name of the Vulnerable Software and Affected Versions mcp/sdk versions 0.5.0 through 0.7.0 Description The HTTP client transport in the MCP PHP SDK reads a Server-Sent Events SSE response stream incrementally and appends data to an in-memory buffer sseBuffer without an upper bound. The buffer is...

CVE-2026-56280 Cap-go - Privilege Inversion in Build Log Stream via SSE Disconnect

Cap-go before 12.128.2 contains a privilege inversion vulnerability in GET /build/logs/:jobId that allows read-only API key holders to cancel running native builds. The endpoint registers an abort listener on the SSE stream that unconditionally invokes cancelBuildOnDisconnect using the privileged...

GHSA-36XV-JGW5-4Q75 @nestjs/core Improperly Neutralizes Special Elements in Output Used by a Downstream Component ('Injection')

Impact What kind of vulnerability is it? Who is impacted? SseStream.transform interpolates message.type and message.id directly into Server-Sent Events text protocol output without sanitizing newline characters \r, \n. Since the SSE protocol treats both \r and \n as field delimiters and \n\n as...

CVE-2026-33946 MCP Ruby SDK: Insufficient Session Binding Allows SSE Stream Hijacking via Session ID Replay

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's...

CVE-2026-31950 LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats

LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint /api/agents/chat/stream/:streamId does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and...

CVE-2026-31950 LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats

LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint /api/agents/chat/stream/:streamId does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and...

CVE-2026-33946: Session Fixation

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's...