PT-2026-56559 · Nats.Io · Nats Server

Published 2026-07-08 · Updated 2026-07-08 · CVE-2026-58209

NVD

CVSS v3.1

4.3

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, MQTT retained message delivery and QoS1+ durable replay could deliver messages whose original topics matched a subscriber configured subscribe deny rule because these delivery paths did not consistently recheck the concrete original topic before sending the MQTT PUBLISH to the subscriber. This issue is fixed in versions 2.14.3 and 2.12.12.

Fix

Incorrect Authorization

Weakness Enumeration

CWE-863

Related Identifiers

CVE-2026-58209

Affected Products

Nats Server

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2026-58209 · Security Note
• https://github.com/nats-io/nats-server/releases/tag/v2.14.3 · Note
• https://github.com/nats-io/nats-server/security/advisories/GHSA-7qmq-8cc4-hxwg · Note
• https://github.com/nats-io/nats-server/commit/181b1f51f40b9954c57e9d478e051fb257679356 · Note
• https://github.com/nats-io/nats-server/releases/tag/v2.12.12 · Note
• https://github.com/nats-io/nats-server/commit/1c429b6fdc5afd4188cc5faf1127f6334896cd87 · Note