Incorrect authorization in nats-server - CVE-2026-58214
Published: June 30, 2026
Vulnerability identifier: #VU135934
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-58214
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to improper access control in internal $MQTT.deliver.pubrel subjects when processing MQTT subscribe requests. A remote user can subscribe to an internal MQTT delivery subject to disclose sensitive information.
Only MQTT QoS2 protocol metadata for sessions in the account is exposed; message payloads are not exposed through this path.
Affected software
nats-server
How to mitigate CVE-2026-58214
Install security update from vendor's website.
nats-server - addressed in versions 2.12.8, 2.14.3