CVE-2026-58214
Fixed in a distro release EPSS <1%CVSS 4.3
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.
Products: nats-io nats-server
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | nats-server | no fix |
| Debian 13 | nats-server | no fix |
| Debian 14 | nats-server | 2.14.3-1 |
| Red Hat hummingbird 1 | nats-server2.12 | 0:2.12.12-1.hum1 |
| Red Hat hummingbird 1 | nats-server2.14 | 0:2.14.3-1.hum1 |
| Ubuntu 24.04 LTS | nats-server | no fix |
| Ubuntu 25.10 | nats-server | no fix |
| Ubuntu 26.10 | nats-server | no fix |
| Ubuntu Pro 26.04 LTS | nats-server | no fix |