nats-io nats-server up to 2.11.14/2.12.5 MQTT Client Interface improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.1$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in nats-io nats-server up to 2.11.14/2.12.5. This affects an unknown part of the component MQTT Client Interface. Performing a manipulation results in improper authentication. This vulnerability was named CVE-2026-33215. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in nats-io nats-server up to 2.11.14/2.12.5. This affects some unknown functionality of the component MQTT Client Interface. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-33215 since 03/18/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 2.11.15 or 2.12.6 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.2
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.6
VulDB Temp Score: 5.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔒

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: nats-server 2.11.15/2.12.6

Timelineinfo

03/18/2026 CVE reserved
03/25/2026 +7 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
03/29/2026 +4 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-fcjp-h8cc-6879
Status: Confirmed

CVE: CVE-2026-33215 (🔒)
GCVE (CVE): GCVE-0-2026-33215
GCVE (VulDB): GCVE-100-352893

Entryinfo

Created: 03/25/2026 07:24
Updated: 03/29/2026 16:06
Changes: 03/25/2026 07:24 (65), 03/29/2026 16:06 (12)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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