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Details of issue NIXPKGS-2026-0764

NIXPKGS-2026-0764
published 3 months ago
Permalink CVE-2026-33219
5.3 MEDIUM
  • CVSS version (CVSS): 3.1
  • Attack Vector (AV): Network (N)
  • Attack Complexity (AC): Low (L)
  • Privileges Required (PR): None (N)
  • User Interaction (UI): None (N)
  • Scope (S): Unchanged (U)
  • Confidentiality (C): None (N)
  • Integrity (I): None (N)
  • Availability (A): Low (L)
  • Modified Attack Vector (MAV): Network (N)
  • Modified Attack Complexity (MAC): Low (L)
  • Modified Privileges Required (MPR): None (N)
  • Modified User Interaction (MUI): None (N)
  • Modified Confidentiality (MC): None (N)
  • Modified Scope (MS): Unchanged (U)
  • Modified Integrity (MI): None (N)
  • Modified Availability (MA): Low (L)
updated 2 months, 4 weeks ago by @LeSuisse Activity log
  • Created suggestion 3 months ago
  • @LeSuisse accepted 2 months, 4 weeks ago
  • @LeSuisse published on GitHub 2 months, 4 weeks 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