CVE-2026-58214NATS Server: MQTT subscribe ACL bypass via $MQTT.deliver.pubrel prefix (incomplete fix for CVE-2026-33217)

Descripción

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.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Referencias y parches

• https://github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfj Vendor Advisory
• https://github.com/nats-io/nats-server/commit/297b166be60fe13144084eed4b25201ead03204a Patch
• https://github.com/nats-io/nats-server/commit/34b09657bb596d5f850eaa5cfc97ea6b2f989a97 Patch
• https://github.com/nats-io/nats-server/releases/tag/v2.12.12 Release Notes
• https://github.com/nats-io/nats-server/releases/tag/v2.14.3 Release Notes