NATS Server: Incomplete Stripping of Nats-Request-Info Header Allows Identity Spoofing in github.com/nats-io/nats-server

Open Source Vulnerabilities CVE-2026-33223

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 credentials for any regular client interface could thus spoof their identity to services which rely upon this header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

Open Source Vulnerabilities GO-2026-4835

NATS Server: Incomplete Stripping of Nats-Request-Info Header Allows Identity Spoofing in github.com/nats-io/nats-server

Open Source Vulnerabilities BIT-nats-2026-33223

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 credentials for any regular client interface could thus spoof their identity to services which rely upon this header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

Open Source Vulnerabilities GHSA-pwx7-fx9r-hr4h

### 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 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 credentials for any regular client interface could thus spoof their identity to services which rely upon this header. ### Affected Versions Any version before v2.12.6 or v2.11.15 ### Workarounds None.