CVE•Published 2026-03-25•Modified 2026-06-30•0 articles on news•6 live references•NVD data

CVE-2026-33218Linuxfoundation · Nats-server

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

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

EPSS percentile

—

Weaknesses (CWE)

CWE-20Improper Input Validation CWE-1286Improper Validation of Syntactic Correctness of Input

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.

Timeline

Published 2026-03-25

Modified 2026-06-30

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-33218

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Linuxfoundation Nats-server"

All exposed Linuxfoundation Nats-server instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Nats-server"

HTTP body or banner mentions "Nats-server" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-33218