CVE-2026-33217 NATS allows MQTT clients to bypass ACL checks

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, when using ACLs on message subjects, these ACLs were not applied in the $MQTT. namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. Versions...

CVE-2026-33217

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, when using ACLs on message subjects, these ACLs were not applied in the $MQTT. namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. Versions...

CVE-2026-33216

Impactful CVE-2026-33216 (NATS-Server) : In MQTT deployments using usercodes/passwords, passwords are incorrectly classified as a non-authenticating identity statement (JWT) and exposed through monitoring endpoints. Affected versions are prior to 2.11.15 and 2.12.6; fixes are in 2.11.14 and 2.12....

CVE-2026-33216

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-2026-33216 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-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-2026-33216

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 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 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 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

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

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...

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-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...