{"id":"DEBIAN-CVE-2026-33219","details":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, a malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment.","modified":"2026-09-10T08:47:27.989202646Z","published":"2026-03-25T20:16:32.777Z","upstream":["CVE-2026-33219"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-33219"}],"affected":[{"package":{"name":"nats-server","ecosystem":"Debian:12","purl":"pkg:deb/debian/nats-server?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.1-1","2.10.16-1","2.10.18-1","2.10.24-1","2.10.27-1","2.10.3-1","2.10.4-1","2.10.7-1","2.12.4-1","2.12.6-1","2.14.1-1","2.14.3-1","2.9.10-1","2.9.19-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33219.json"}},{"package":{"name":"nats-server","ecosystem":"Debian:13","purl":"pkg:deb/debian/nats-server?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.27-1","2.12.4-1","2.12.6-1","2.14.1-1","2.14.3-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33219.json"}},{"package":{"name":"nats-server","ecosystem":"Debian:14","purl":"pkg:deb/debian/nats-server?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12.6-1"}]}],"versions":["2.10.27-1","2.12.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33219.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}