SB2026111335 - Incorrect authorization in nats-server

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Main Vulnerability Database SB2026111335

SB2026111335 - Incorrect authorization in nats-server

Published: November 13, 2026

Security Bulletin ID SB2026111335
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Incorrect authorization (CVE-ID: N/A)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to bypass source-network restrictions and gain unauthorized access to messaging services from a disallowed network.

The vulnerability exists due to incorrect authorization in nats-server's authorization callout handling when accepting user credentials without enforcing their JWT source-network restrictions. A remote user can connect to a reachable server listener using valid callout-issued credentials from a disallowed source to access messaging services despite those restrictions.

The subject permissions returned by the authorization callout remain enforced.


Remediation

Install update from vendor's website.

References