SB20260422222 - Multiple vulnerabilities in nats-server

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Main Vulnerability Database SB20260422222

SB20260422222 - Multiple vulnerabilities in nats-server

Published: April 22, 2026 Updated: April 23, 2026

Security Bulletin ID SB20260422222
CSH Severity
High
Patch available
YES
Number of vulnerabilities 11
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

High 18% Medium 64% Low 18%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 11 vulnerabilities.


1) Incorrect authorization (CVE-ID: CVE-2026-33249)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass authorization process.

The vulnerability exists due to incorrect authorization. A remote user can redirect message tracing to arbitrary subject.


2) Unprotected storage of credentials (CVE-ID: CVE-2026-33216)

CWE-ID: CWE-256 - Unprotected Storage of Credentials

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to gain access to other users' credentials.

The vulnerability exists due to application stored credentials in plain text within MQTT. A remote attacker can gain access to sensitive information on the system.


3) Incorrect authorization (CVE-ID: CVE-2026-33217)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass authorization checks.

The vulnerability exists due to insufficient authorization controls. A remote user can bypass ACL checks for MQTT subjects


4) Improper Authentication (CVE-ID: CVE-2026-33246)

CWE-ID: CWE-287 - Improper Authentication

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to improper authentication within leafnode connections. A remote user can spoof the Nats-Request-Info identity headers.


5) Input validation error (CVE-ID: CVE-2026-33218)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in the leafnode port. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


6) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-33219)

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to allocation of resources without limits or throttling within WebSockets client service. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


7) Authentication Bypass by Spoofing (CVE-ID: CVE-2026-33223)

CWE-ID: CWE-290 - Authentication Bypass by Spoofing

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to incomplete stripping of Nats-Request-Info header. A remote user can spoof their identity to services which rely upon this header.


8) Improper Authorization (CVE-ID: CVE-2026-33222)

CWE-ID: CWE-285 - Improper Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to bypass authorization checks.

The vulnerability exists due to insufficient authorization controls in Management API. A remote administrator can bypass the stream restore endpoint.


9) Improper Authentication (CVE-ID: CVE-2026-33248)

CWE-ID: CWE-287 - Improper Authentication

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to incorrect Subject DN matching. A remote attacker can bypass authentication process and gain unauthorized access to the application.


10) Insertion of Sensitive Information Into Debugging Code (CVE-ID: CVE-2026-33247)

CWE-ID: CWE-215 - Insertion of Sensitive Information Into Debugging Code

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to credentials via command-line argv exposed to monitoring. A remote attacker can gain access to sensitive information on the system.


11) Improper Authentication (CVE-ID: CVE-2026-33215)

CWE-ID: CWE-287 - Improper Authentication

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to the MQTT hijacking issue via Client ID. A remote attacker can hijack sessions and messages on the target system.


Remediation

Install update from vendor's website.

References