CVE-2026-67431 MCP Ruby SDK: Ruby SSE Session Poisoning

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not bind a session ID to a session owner, allowing an attacker with a stolen session ID to send tools/call requests that...

CVE-2026-67431 MCP Ruby SDK: Ruby SSE Session Poisoning

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not bind a session ID to a session owner, allowing an attacker with a stolen session ID to send tools/call requests that...

CVE-2026-63119 MCP Ruby SDK: Unbounded line buffer in stdio transports leads to memory exhaustion (DoS)

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StdioTransport and MCP::Client::Stdio in the mcp gem use IOgets without a byte limit, allowing a peer that sends data without a newline to exhaust process memory. This...

CVE-2026-63119

The CVE affects the MCP Ruby SDK (mcp gem), specifically MCP::Server::Transports::StdioTransport and MCP::Client::Stdio. The vulnerability arises from using IO#gets without a byte limit, allowing an attacker to send data without a newline and trigger unbounded line buffering, causing memory exhau...

CVE-2026-67430

CVE-2026-67430 affects the MCP Ruby SDK (mcp gem) prior to 0.23.0. The vulnerability is in MCP::Server::Transports::StreamableHTTPTransport, which does not expire sessions by default, allowing repeated initialize requests to retain unbounded ServerSession objects and cause memory exhaustion. The ...

CVE-2026-67430 MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not expire sessions by default, so repeated initialize requests retain unbounded ServerSession objects and can exhaust proces...

USN-8624-1 ruby-sinatra vulnerability

It was discovered that Sinatra did not properly handle header parsing, causing ETag generation to hang when given specific input. A remote attacker could possibly use this issue to cause a denial of service...

CVE-2026-63118

The MCP Ruby SDK (mcp gem) contains a DNS rebind vulnerability in MCP::Server::Transports::StreamableHTTPTransport where HTTP Host/Origin are not validated. This allows a malicious page to bind a victim’s locally running MCP server to a loopback/ LAN address and post JSON‑RPC requests to exposed ...

CVE-2026-63118 MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not validate the HTTP Host or Origin request headers, which allows a malicious browser page to use DNS rebinding to reach a...

Low: Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

An update for Red Hat Hardened Images RPMs is now available. This update includes the following RPMs: ruby4.0: ruby4.0-4.0.6-37.1.hum1 aarch64, x8664 ruby4.0-bundled-gems-4.0.6-37.1.hum1 aarch64, x8664 ruby4.0-default-gems-4.0.6-37.1.hum1 noarch ruby4.0-devel-4.0.6-37.1.hum1 aarch64, x8664...

json: Ruby JSON: Denial of service via heap buffer overflow with oversized streamed objects

A flaw was found in Ruby JSON. A remote attacker could exploit a heap buffer overflow vulnerability by providing an oversized streamed object containing a specially crafted string. This could lead to a reliable process crash, resulting in a denial of service DoS for the affected system...

PT-2026-65899

Name of the Vulnerable Software and Affected Versions mcp versions prior to 0.23.0 Description The MCP::Server::Transports::StreamableHTTPTransport component in the mcp gem reads and parses an entire JSON-RPC POST body without enforcing a size limit. This allows an unauthenticated remote attacker...

PT-2026-65888

Name of the Vulnerable Software and Affected Versions mcp versions prior to 0.23.0 Description The MCP::Server::Transports::StreamableHTTPTransport component in the mcp gem fails to validate the HTTP Host or Origin request headers. This allows a malicious browser page to utilize DNS rebinding—a...

UBUNTU-CVE-2026-54619

sqlite3 provides Ruby bindings for the SQLite3 embedded database. In v...

UBUNTU-CVE-2026-54620

sqlite3 provides Ruby bindings for the SQLite3 embedded database. From...

UBUNTU-CVE-2026-54605

OAuth is a Ruby wrapper for the OAuth 1.0 and 1.0a protocols, providin...

PT-2026-65897

Name of the Vulnerable Software and Affected Versions mcp versions prior to 0.23.0 Description The MCP::Server::Transports::StreamableHTTPTransport component in the mcp gem does not expire sessions by default. Consequently, repeated initialize requests lead to the retention of unbounded...

UBUNTU-CVE-2026-54603

OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frame...

CVE-2026-54603

creationtimestamp| type| source ---|---|--- 2026-07-28 18:35:08+00:00| published-proof-of-concept| https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9 2026-07-28 20:31:48+00:00| seen| https://gist.github.com/alon710/76a4f64bf3e94be3974678cdc55c68d9...

DEBIAN-CVE-2026-54620

sqlite3 provides Ruby bindings for the SQLite3 embedded database. From 2.1.0 to 2.9.4, the callbacks used for SQLite aggregate functions can be freed while still referenced during aggregation, resulting in a use-after-free. This issue is fixed in version 2.9.5...