{"id":"CVE-2026-58214","title":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system","summary":"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 co…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-863"],"vendor":"linuxfoundation","product":"nats-server","affected":["nats-server < 2.12.12","nats-server >= 2.14.0, < 2.14.3"],"patched":["nats-server 2.14.3"],"published":"2026-07-08","updated":"2026-07-13","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-58214","references":[{"url":"https://github.com/nats-io/nats-server/commit/297b166be60fe13144084eed4b25201ead03204a","label":"security-advisories@github.com"},{"url":"https://github.com/nats-io/nats-server/commit/34b09657bb596d5f850eaa5cfc97ea6b2f989a97","label":"security-advisories@github.com"},{"url":"https://github.com/nats-io/nats-server/releases/tag/v2.12.12","label":"security-advisories@github.com"},{"url":"https://github.com/nats-io/nats-server/releases/tag/v2.14.3","label":"security-advisories@github.com"},{"url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfj","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00349,"epssPercentile":0.28465,"ingestedAt":"2026-07-13T15:27:34.246Z","slug":"CVE-2026-58214","body":"## Overview\n\nNATS 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.\n\n## Affected\n\n- `nats-server < 2.12.12`\n- `nats-server >= 2.14.0, < 2.14.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `nats-server 2.14.3`","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}