Improper Authorization in nats-server - #VU135925
Published: June 30, 2026
Vulnerability identifier: #VU135925
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-285
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: NATS - The Cloud Native Messaging System
Affected software:
nats-server
nats-server
Detailed vulnerability description
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to improper authorization in the subscription permission system when processing wildcard subscription requests that overlap with wildcard deny rules. A remote user can create a wildcard subscription to receive messages on denied subjects to disclose sensitive information.
The issue requires valid credentials and a permission configuration with overlapping wildcard allow and deny patterns. Queue subscriptions may also affect delivery to legitimate queue consumers.
Remediation
Install security update from vendor's website.