CVE-2026-58209
Published:July 08, 2026
Updated:August 04, 2026
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.
Affected Packages
https://github.com/nats-io/nats-server.git (GITHUB):
Affected version(s) >=v2.14.0 <v2.14.3Fix Suggestion:
Update to version v2.14.3https://github.com/nats-io/nats-server.git (GITHUB):
Affected version(s) >=v0.5.1 <v2.12.12Fix Suggestion:
Update to version v2.12.12github.com/nats-io/nats-server/v2 (GO):
Affected version(s) >=v2.14.0 <v2.14.3Fix Suggestion:
Update to version v2.14.3github.com/nats-io/nats-server/v2 (GO):
Affected version(s) >=v2.0.0-RC14.0.20190604014547-ed1901c79292 <v2.12.12Fix Suggestion:
Update to version v2.12.12Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Incorrect Authorization
EPSS
Base Score:
0.25