4.3

CVE-2026-58214

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

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linuxfoundation ≫ Nats-server Version < 2.12.12
Linuxfoundation ≫ Nats-server Version >= 2.14.0 < 2.14.3
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.26% 0.172
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 4.3 2.8 1.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CWE-863 Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

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
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/security/advisories/GHSA-4g68-3pwx-5vfj
Vendor Advisory