{"id":"GHSA-fcjp-h8cc-6879","summary":"NATS is vulnerable to MQTT hijacking via Client ID","details":"### Background\n\nNATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing.\n\nThe nats-server provides an MQTT client interface.\n\n### Problem Description\n\nSessions and Messages can by hijacked via MQTT Client ID malfeasance.\n\n### Affected Versions\n\nAny version before v2.12.6 or v2.11.15\n\n### Workarounds\n\nNone.\n\n### Resources\n\n * This document is canonically: \u003chttps://advisories.nats.io/CVE/secnote-2026-06.txt\u003e\n * GHSA advisory: \u003chttps://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879\u003e\n * MITRE CVE entry: \u003chttps://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-33215\u003e","aliases":["BIT-nats-2026-33215","CVE-2026-33215","GO-2026-4833"],"modified":"2026-09-10T03:51:00.306717387Z","published":"2026-03-24T21:39:52Z","database_specific":{"github_reviewed_at":"2026-03-24T21:39:52Z","nvd_published_at":"2026-03-24T21:16:28Z","cwe_ids":["CWE-287"],"severity":"MODERATE","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33215"},{"type":"WEB","url":"https://advisories.nats.io/CVE/secnote-2026-06.tx"},{"type":"PACKAGE","url":"https://github.com/nats-io/nats-server"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2026-4833"}],"affected":[{"package":{"name":"github.com/nats-io/nats-server/v2","ecosystem":"Go","purl":"pkg:golang/github.com/nats-io/nats-server/v2"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.11.15"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-fcjp-h8cc-6879/GHSA-fcjp-h8cc-6879.json"}},{"package":{"name":"github.com/nats-io/nats-server/v2","ecosystem":"Go","purl":"pkg:golang/github.com/nats-io/nats-server/v2"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.12.0-RC.1"},{"fixed":"2.12.6"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-fcjp-h8cc-6879/GHSA-fcjp-h8cc-6879.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L"}]}