CVE-2026-33219

March 26, 2026, 5:15 p.m.

5.3
Medium

Description

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.

Product(s) Impacted

Vendor Product Versions
Linuxfoundation
  • Nats-server
  • *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-770
Allocation of Resources Without Limits or Throttling
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a linuxfoundation nats-server / / / / / / / /
a linuxfoundation nats-server / / / / / / / /

References

https://advisories.nats.io/CVE/secnote-2026-02.txt
https://advisories.nats.io/CVE/secnote-2026-11.txt
https://github.com/advisories/GHSA-qrvq-68c2-7grw
https://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7j

Tags

[email protected]
CWE-770
2026-03-25
CVE-2026-33219

CVSS Score

5.3 / 10

CVSS Data - 3.1

  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Privileges Required: NONE
  • Scope: UNCHANGED
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: LOW

    • CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

    View Vector String

Timeline

Published: March 25, 2026, 8:16 p.m.
Last Modified: March 26, 2026, 5:15 p.m.

Status : Analyzed

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.