CVE-2026-58250

CVE-2026-58250 affects NATS Server: an unauthenticated peer with access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO messages. The issue is fixed in versions 2.12.8 and 2.11.17 . Exploitat...

CVE-2026-58250 NATS Server: Pre-auth server crash via double INFO in leafnode handshake

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by...

CVE-2026-58250 NATS Server: Pre-auth server crash via double INFO in leafnode handshake

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by...

CVE-2026-58250 NATS Server: Pre-auth server crash via double INFO in leafnode handshake

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by...

EUVD-2026-42375

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

CVE-2026-58253

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

CVE-2026-58253 NATS Server: Route API Auth Bypass

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

PT-2026-56566

Name of the Vulnerable Software and Affected Versions NATS Server versions prior to 2.14.3 NATS Server versions prior to 2.12.8 Description Message trace destination checks are not consistently applied to messages arriving through leafnode connections. This allows a leafnode operator to send trac...

PT-2026-56565

Name of the Vulnerable Software and Affected Versions NATS Server versions prior to 2.14.0 NATS Server versions prior to 2.12.7 NATS Server versions prior to 2.11.16 Description When no auth user is configured, a parser fast path designed for standard client connections may incorrectly apply to...

CVE-2026-58253: Improper Authentication

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

CVE-2026-58254: Incorrect Authorization

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.8, message trace destination checks were applied to ordinary client connections but not consistently to messages arriving through leafnode connections, allowing a leafnode...

PT-2026-56563

Name of the Vulnerable Software and Affected Versions NATS Server versions prior to 2.12.8 NATS Server versions prior to 2.11.17 Description An unauthenticated peer with network access to a leafnode listener with compression enabled can cause the server to crash. This occurs during the...

CVE-2026-58250: NULL Pointer Dereference

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by...

nats-server: NATS Server: Denial of Service via inconsistent message trace destination checks

A flaw was found in NATS Server. Message trace destination checks, which ensure that trace events are sent to authorized subjects, were not consistently applied to messages originating from leafnode connections. This inconsistency allows a leafnode operator to bypass these checks and send trace...

nats-server: NATS Server: Denial of Service via inconsistent message trace destination checks

A flaw was found in NATS Server. Message trace destination checks, which ensure that trace events are sent to authorized subjects, were not consistently applied to messages originating from leafnode connections. This inconsistency allows a leafnode operator to bypass these checks and send trace...

NATS Server panic via malicious compression on leafnode port

...

BIT-NATS-2026-33246 NATS: Leafnode connections allow spoofing of Nats-Request-Info identity headers

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...

BIT-NATS-2026-33218 NATS has pre-auth server panic via leafnode handling

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 ...

BIT-NATS-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...

SUSE 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...