NATS has mTLS verify_and_map authentication bypass via incorrect Subject DN matching

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. One authentication model supported is mTLS, deriving the NATS client identity from properties of the TLS Client Certificate. Problem...

Improper Certificate Validation

Overview Affected versions of this package are vulnerable to Improper Certificate Validation through the RDNsMatch LDAP DN matching function in the internal/ldap component. An attacker can impersonate a trusted client and gain unauthorized access by presenting a certificate with a different set o...

GHSA-3F24-PCVM-5JQC NATS has mTLS verify_and_map authentication bypass via incorrect Subject DN matching

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. One authentication model supported is mTLS, deriving the NATS client identity from properties of the TLS Client Certificate. Problem...

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...

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...

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...

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...

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...

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...

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 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...

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...

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...

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...

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...