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Details of issue NIXPKGS-2026-0764

NIXPKGS-2026-0764
published on
Permalink CVE-2026-33219
5.3 MEDIUM
  • 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): LOW
updated 1 month, 1 week ago by @LeSuisse Activity log
  • Created suggestion 1 month, 1 week ago
  • @LeSuisse accepted 1 month, 1 week ago
  • @LeSuisse published on GitHub 1 month, 1 week ago
NATS is vulnerable to pre-auth DoS through WebSockets client service

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-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment.

Affected products

nats-server
  • ==< 2.11.15
  • ==>= 2.12.0-RC.1, < 2.12.6

Matching in nixpkgs

Package maintainers

Upstream advisory: https://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7j