User Impersonation

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to User Impersonation through the processServiceImport request-info header handling in leafnode...

User Impersonation

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to User Impersonation via incomplete removal of the Nats-Request-Info header. An attacker can...

NATS Server: Incomplete Stripping of Nats-Request-Info Header Allows Identity Spoofing

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server offers a Nats-Request-Info: message header, providing information about a request. Problem Description The NATS message head...

Incorrect Authorization

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Incorrect Authorization via the Management API restore process. An attacker can modify or...

Allocation of Resources Without Limits or Throttling

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling through the checkBytesLimits,...

NATS is vulnerable to pre-auth DoS through WebSockets client service

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server offers a WebSockets client service, used in deployments where browsers are the NATS clients. Problem Description A malicious...

Improper Handling of Unexpected Data Type

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Improper Handling of Unexpected Data Type through the leafnode connection handling in...

NATS has pre-auth server panic via leafnode handling

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server allows hub/spoke topologies using "leafnode" connections by other nats-servers. Problem Description A client which can conne...

GHSA-VPRV-35VV-Q339 NATS has pre-auth server panic via leafnode handling

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server allows hub/spoke topologies using "leafnode" connections by other nats-servers. Problem Description A client which can conne...

Incorrect Authorization

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Incorrect Authorization due to improper enforcement of access control in the $MQTT. namespac...

NATS allows MQTT clients to bypass ACL checks

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server provides an MQTT client interface. Problem Description When using ACLs on message subjects, these ACLs were not applied in t...

Credential Exposure

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Credential Exposure through the MQTT authentication processing in...

NATS has MQTT plaintext password disclosure

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server provides an MQTT client interface. Problem Description For MQTT deployments using usercodes/passwords: MQTT passwords are...

GHSA-V722-JCV5-W7MC NATS has MQTT plaintext password disclosure

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server provides an MQTT client interface. Problem Description For MQTT deployments using usercodes/passwords: MQTT passwords are...

EUVD-2026-15017

NATS is vulnerable to MQTT hijacking via Client ID...

GHSA-FCJP-H8CC-6879 NATS is vulnerable to MQTT hijacking via Client ID

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server provides an MQTT client interface. Problem Description Sessions and Messages can by hijacked via MQTT Client ID malfeasance...

NATS is vulnerable to MQTT hijacking via Client ID

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server provides an MQTT client interface. Problem Description Sessions and Messages can by hijacked via MQTT Client ID malfeasance...

NULL Pointer Dereference

Overview github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to NULL Pointer Dereference via the compression process on the leafnode port. An attacker can...

NATS Server panic via malicious compression on leafnode port

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 configured to accept leafnode connections for a hub/spoke topology of multiple nats-servers, then the default configuration allows for...

CVE-2026-33215

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server provides an MQTT client interface. Prior to versions 2.11.15 and 2.12.5, Sessions and Messages can by hijacked via MQTT Client ID malfeasance. Versions 2.11.15 and 2.12.5 patch the issu...