Vulnerability Description
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 trust a message, provided that they trust the nats-server as a broker. A leafnode connecting to a nats-server is not fully trusted unless the system account is bridged too. Thus identity claims should not have propagated unchecked. Prior to versions 2.11.15 and 2.12.6, NATS clients relying upon the Nats-Request-Info: header could be spoofed. This does not directly affect the nats-server itself, but the CVSS Confidentiality and Integrity scores are based upon what a hypothetical client might choose to do with this NATS header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linuxfoundation | Nats-Server | < 2.11.15 |
Related Weaknesses (CWE)
References
- https://advisories.nats.io/CVE/secnote-2026-08.txtVendor Advisory
- https://github.com/nats-io/nats-server/security/advisories/GHSA-55h8-8g96-x4hjVendor Advisory
FAQ
What is CVE-2026-33246?
CVE-2026-33246 is a vulnerability with a CVSS score of 6.4 (MEDIUM). 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. Thi...
How severe is CVE-2026-33246?
CVE-2026-33246 has been rated MEDIUM with a CVSS base score of 6.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-33246?
Check the references section above for vendor advisories and patch information. Affected products include: Linuxfoundation Nats-Server.