Nixpkgs security tracker

Login with GitHub

Details of issue NIXPKGS-2026-0761

NIXPKGS-2026-0761
published on
Permalink CVE-2026-27889
7.5 HIGH
  • CVSS version: 3.1
  • Attack vector (AV): NETWORK
  • Attack complexity (AC): LOW
  • Privileges required (PR): NONE
  • User interaction (UI): NONE
  • Scope (S): UNCHANGED
  • Confidentiality impact (C): NONE
  • Integrity impact (I): NONE
  • Availability impact (A): HIGH
updated 1 month, 1 week ago by @LeSuisse Activity log
  • Created suggestion
  • @LeSuisse accepted
  • @LeSuisse published on GitHub
NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead

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.

Affected products

nats-server
  • ==>= 2.12.0, < 2.12.5
  • ==>= 2.2.0, < 2.11.14

Matching in nixpkgs

Package maintainers

Upstream advisory: https://github.com/nats-io/nats-server/security/advisories/GHSA-pq2q-rcw4-3hr6