CVE-2026-33216 NATS has MQTT plaintext password disclosure

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, for MQTT deployments using usercodes/passwords: MQTT passwords are incorrectly classified as a non-authenticating identity statement JWT and exposed via monitoring...

CVE-2026-33216 NATS has MQTT plaintext password disclosure

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, for MQTT deployments using usercodes/passwords: MQTT passwords are incorrectly classified as a non-authenticating identity statement JWT and exposed via monitoring...

CVE-2026-29785 NATS Server panic via malicious compression on leafnode port

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled not default, then anyone who can connect can crash the nats-server by triggering a panic. This happens...

CVE-2026-29785 NATS Server panic via malicious compression on leafnode port

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled not default, then anyone who can connect can crash the nats-server by triggering a panic. This happens...

CVE-2026-29785 NATS Server panic via malicious compression on leafnode port

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled not default, then anyone who can connect can crash the nats-server by triggering a panic. This happens...

CVE-2026-29785

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled not default, then anyone who can connect can crash the nats-server by triggering a panic. This happens...

CVE-2026-29785

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled not default, then anyone who can connect can crash the nats-server by triggering a panic. This happens...

CVE-2026-29785

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled not default, then anyone who can connect can crash the nats-server by triggering a panic. This happens...

CVE-2026-29785

CVE-2026-29785 affects the NATS-Server (NATS.io) prior to versions 2.11.14 and 2.12.5. When leafnode is enabled (not default) and compression is enabled (default with leafnodes), an unauthenticated attacker who can connect can crash the server by triggering a panic. The condition is pre-authentic...

CVE-2026-27889 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and...

CVE-2026-27889

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and...

CVE-2026-27889 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and...

CVE-2026-27889

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and...

CVE-2026-27889 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and...

CVE-2026-27889

CVE-2026-27889 pertains to the NATS server when WebSockets are enabled. A pre-authentication remote crash can be triggered by a crafted WebSocket frame with a 64-bit extended payload length MSB set, which causes a signed/unsigned handling issue and results in an unrecovered panic, terminating the...

NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. When using WebSockets, a malicious client can trigger a server crash with crafted frames, before authentication. Problem Description A missi...

GHSA-PQ2Q-RCW4-3HR6 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. When using WebSockets, a malicious client can trigger a server crash with crafted frames, before authentication. Problem Description A missi...

Integer Overflow or Wraparound

Overview github.com/nats-io/nats-server/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Integer Overflow or Wraparound via the wsRead function. An attacker can cause the server proces...

CVE-2026-33218: Improper Input Validation

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, a client which can connect to the leafnode port can crash the nats-server with a certain malformed message pre-authentication. Versions 2.11.15 and 2.12.6 contain ...

CVE-2026-33246: Improper Authentication

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a Nats-Request-Info: message header, providing information about a request. This is supposed to provide enough information to allow for account/user identification, such that NAT...