CVE-2026-33218

Published: Mar 25, 2026

Modified: Mar 26, 2026

PUBLISHED

CVSS v3.1

7.5

HIGH

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 client which can connect to the leafnode port can crash the nats-server with a certain malformed message pre-authentication. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable leafnode support if not needed or restrict network connections to the leafnode port, if plausible without compromising the service offered.

Vendor	Product	Versions
nats-io	nats-server	affected `< < 2.11.15` affected `>= 2.12.0-RC.1, < 2.12.6`

Weaknesses (CWE)

CWE-20

CVSS v3.1 Details

CVSS v3.1 Vector

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

References

https://github.com/nats-io/nats-server/security/advisories/GHSA-vprv-35vv-q339

x_refsource_CONFIRM

https://advisories.nats.io/CVE/secnote-2026-10.txt

x_refsource_MISC

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CVE-2026-33218

Description

Affected Products

Weaknesses (CWE)

CVSS v3.1 Details

References