PT-2026-27614 · Nats.Io · Nats Server

Published 2026-03-24 · Updated 2026-05-21 · CVE-2026-33217

Positive Technologies (AI Summary)

CVSS v3.1

7.1

High

Base vector

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

Name of the Vulnerable Software and Affected Versions NATS-Server versions prior to 2.11.15 NATS-Server versions prior to 2.12.6

Description NATS-Server is a high-performance server for NATS.io, a cloud and edge native messaging system. When using Access Control Lists (ACLs) on message subjects, these ACLs were not applied in the $MQTT.> namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. This issue affects the MQTT client interface provided by nats-server. No known workarounds are available.

Recommendations Update to NATS-Server version 2.11.15 or later. Update to NATS-Server version 2.12.6 or later.

Exploit

Fix

Incorrect Authorization

Weakness Enumeration

CWE-863

Related Identifiers

BIT-NATS-2026-33217

CVE-2026-33217

GHSA-JXXM-27VP-C3M5

GO-2026-4834

SUSE-SU-2026:1135-1

Affected Products

Nats Server

References · 156

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33217.json · Exploit
• https://github.com/nats-io/nats-server/security/advisories/GHSA-jxxm-27vp-c3m5 · Vendor Advisory
• https://advisories.nats.io/CVE/secnote-2026-07.txt · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-33217 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2026:1135-1 · Vendor Advisory
• https://osv.dev/vulnerability/BIT-nats-2026-33217 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-33217 · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4834 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-33217 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-33217 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-33217 · Security Note
• https://osv.dev/vulnerability/ROOT-APP-GOBINARY-CVE-2026-33217 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-jxxm-27vp-c3m5 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-33217 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-33217 · Security Note