CVE-2026-58252: nats-server before 2.11.16 (exclusive), from 2.12.0 (inclusive), before 2.12.7 (exclusive), < 2.11.16, >=…

Affected technology

nats-server · before 2.11.16 (exclusive)
linuxfoundation

nats-server · from 2.12.0 (inclusive), before 2.12.7 (exclusive)
linuxfoundation

nats-server · < 2.11.16, >= 2.12.0-preview.1, < 2.12.7
nats-io

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · Low privileges required · No user interaction required

What an attacker can do

An authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset of it, and queue subscriptions could also affect delivery to legitimate queue consumers. Vendor/CNA’s CVSS 3.1 assessment (base score 6.5/10) rates confidentiality impact as high; integrity and availability impact as none.