Description

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and so is exposed to anyone who can connect to the websockets port. Versions 2.11.14 and 2.12.5 contains a fix. A workaround is available. The vulnerability only affects deployments which use WebSockets and which expose the network port to untrusted end-points. If one is able to do so, a defense in depth of restricting either of these will mitigate the attack.

INFO

Published Date :

2026-03-25T19:36:36.370Z

Last Modified :

2026-03-25T20:06:31.897Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2026-27889 vulnerability.

Vendors Products
Linuxfoundation
  • Nats-server
Nats
  • Nats Server
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-27889.

URL Resource
https://advisories.nats.io/CVE/secnote-2026-03.txt cve-icon cve-icon cve-icon
https://github.com/nats-io/nats-server/security/advisories/GHSA-pq2q-rcw4-3hr6 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-27889 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-27889 cve-icon
Login to claim this CVE

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact