Linuxfoundation Nats-Server vulnerabilities

CVE-2026-58252 [MEDIUM] CWE-285 CVE-2026-58252: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Pr 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, an authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset of it, and queue subscriptions could also affect deli

CVE-2022-26652 [MEDIUM] CWE-22 CVE-2022-26652: NATS nats-server before 2.7.4 allows Directory Traversal (with write access) via an element in a ZIP NATS nats-server before 2.7.4 allows Directory Traversal (with write access) via an element in a ZIP archive for JetStream streams. nats-streaming-server before 0.24.3 is also affected.

CVE-2026-58207 [MEDIUM] CWE-190 CVE-2026-58207: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Pr NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a client able to send account-scoped connection monitoring requests could crash the server by supplying Connz pagination Offset and Limit values that overflowed internal arithmetic before the response window was safely bound

CVE-2026-33217 [MEDIUM] CWE-863 CVE-2026-33217: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prio 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 2.11.15 and 2.12.6 contain a fix. No known workaround

CVE-2022-29946 [MEDIUM] CVE-2022-29946: NATS NATS.io NATS Server before 2.8.2 and Streaming Server before 0.24.6 could allow a remote attacker to bypass security restrictions, caused by the failure to enforce negative user permissions in one scenario. By using a queue subscription on the wildcard, an attacker could exploit this vulnerability to allow denied subjects.

CVE-2026-58254 [MEDIUM] CVE-2026-58254: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Pr 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 operator to send trace events to subjects that would not otherwi

CVE-2026-33215 [MEDIUM] CWE-287 CVE-2026-33215: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The 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 issue. No known workarounds are available.

CVE-2020-26521 [HIGH] CWE-476 CVE-2020-26521: The JWT library in NATS nats-server before 2.1.9 allows a denial of service (a nil dereference in Go The JWT library in NATS nats-server before 2.1.9 allows a denial of service (a nil dereference in Go code).

CVE-2026-33247 [MEDIUM] CWE-215 CVE-2026-33247: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prio 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, if a nats-server is run with static credentials for all clients provided via argv (the command-line), then those credentials are visible to any user who can see the monitoring port, if that too is enabled. The `/debug

CVE-2026-58211 [MEDIUM] CWE-863 CVE-2026-58211: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Pr NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_r

CVE-2026-33219 [MEDIUM] CVE-2026-33219: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prio 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 malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-2

CVE-2026-33223 [MEDIUM] CWE-290 CVE-2026-33223: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prio 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, the NATS message header `Nats-Request-Info:` is supposed to be a guarantee of identity by the NATS server, but the stripping of this header from inbound messages was not fully effective. An attacker with valid credent

CVE-2026-33246 [MEDIUM] CWE-287 CVE-2026-33246: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The 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 NATS clients could make their own decisions on how to tr

CVE-2026-33222 [MEDIUM] CWE-285 CVE-2026-33222: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prio 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, users with JetStream admin API access to restore one stream could restore to other stream names, impacting data which should have been protected against them. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround

CVE-2026-33249 [MEDIUM] CWE-863 CVE-2026-33249: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Star NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.11.0 and prior to versions 2.11.15 and 2.12.6, a valid client which uses message tracing headers can indicate that the trace messages can be sent to an arbitrary valid subject, including those to which the client does not have publis

CVE-2026-58214 [MEDIUM] CVE-2026-58214: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Pr NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an authenticated MQTT client could subscribe to the internal $MQTT.deliver.pubrel subject family, bypassing configured subscribe permissions and exposing MQTT QoS2 protocol metadata for sessions in the account. This issue is fixed i

CVE-2026-33248 [MEDIUM] CWE-287 CVE-2026-33248: NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prio 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 mTLS for client identity, with `verify_and_map` to derive a NATS identity from the client certificate's Subject DN, certain patterns of RDN would not be correctly enforced, allowing for authentication bypas

CVE-2026-58209 [MEDIUM] CWE-863 CVE-2026-58209: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Pr NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, MQTT retained message delivery and QoS1+ durable replay could deliver messages whose original topics matched a subscriber configured subscribe deny rule because these delivery paths did not consistently recheck the concrete