medium4.3
CVE-2026-58214
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system.
Impact
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, an authenticated MQTT client could subscribe to the internal $MQTT.deliver.pubrel subject family, bypassing configured subscribe permissions and exposing MQTT QoS2 protocol metadata for sessions in the account. This issue is fixed in versions 2.14.3 and 2.12.12.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Linuxfoundation | Nats-Server | before 2.12.12 from 2.14.0 before 2.14.3 |
Weakness classification
References
- NVD record
- CVE.org record
- https://github.com/nats-io/nats-server/commit/297b166be60fe13144084eed4b25201ead03204a
- https://github.com/nats-io/nats-server/commit/34b09657bb596d5f850eaa5cfc97ea6b2f989a97
- https://github.com/nats-io/nats-server/releases/tag/v2.12.12
- https://github.com/nats-io/nats-server/releases/tag/v2.14.3
- https://github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfj