CVE-2026-33215 | BDVDB-2026-322295 Detail

nats-ionats-server

Description#

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server provides an MQTT client interface. Prior to versions 2.11.15 and 2.12.5, Sessions and Messages can by hijacked via MQTT Client ID malfeasance. Versions 2.11.15 and 2.12.5 patch the issue. No known workarounds are available.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact none, availability impact low. Attack vector: network.

Weaknesses#

CWE-287 Improper Authentication
CWE-488 Exposure of Data Element to Wrong Session

References#

Exploit#

No public exploit known

History#

Version 12026-03-24Record published in the CVE List.
Version 22026-03-25Most recent update recorded in the CVE List.

Published

Published: 2026-03-24
Last modified: 2026-03-25

Vendor information

Vendor: nats-io
Product: nats-server

All nats-io vulnerabilities

Score

6.5 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 16.4.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Authentication Issues

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 2.11.15
Fixed
Not stated
Vulnerable
>= 2.12.0-RC.1, < 2.12.6
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

6.5 Medium

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

Metric breakdown
Attack Vector	Network
Attack Complexity	High
Privileges Required	None
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	None
Availability	Low

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).