{"id":"BIT-nats-2026-58214","summary":"NATS Server: MQTT subscribe ACL bypass via $MQTT.deliver.pubrel prefix (incomplete fix for CVE-2026-33217)","details":"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.","aliases":["CVE-2026-58214","GHSA-4g68-3pwx-5vfj"],"modified":"2026-09-29T10:00:06.548936940Z","published":"2026-07-14T15:47:14.889Z","database_specific":{"severity":"Medium","cpes":["cpe:2.3:a:nats:nats_server:*:*:*:*:*:*:*:*","cpe:2.3:a:nats:nats_server:*:*:*:*:*:go:*:*"]},"references":[{"type":"FIX","url":"https://github.com/nats-io/nats-server/commit/297b166be60fe13144084eed4b25201ead03204a"},{"type":"FIX","url":"https://github.com/nats-io/nats-server/commit/34b09657bb596d5f850eaa5cfc97ea6b2f989a97"},{"type":"ARTICLE","url":"https://github.com/nats-io/nats-server/releases/tag/v2.12.12"},{"type":"ARTICLE","url":"https://github.com/nats-io/nats-server/releases/tag/v2.14.3"},{"type":"ADVISORY","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfj"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58214"}],"affected":[{"package":{"name":"nats","ecosystem":"Bitnami","purl":"pkg:bitnami/nats"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.12.12"},{"introduced":"2.14.0"},{"fixed":"2.14.3"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/nats/BIT-nats-2026-58214.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"}]}],"schema_version":"1.9.0"}