{"id":"ALPINE-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":"2026-11-03T06:33:02.351045399Z","published":"2026-03-25T20:16:32.777Z","upstream":["CVE-2026-33219"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2026-33219"}],"affected":[{"package":{"name":"nats-server","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/nats-server?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.12.0"},{"fixed":"2.12.6-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-33219.json"}},{"package":{"name":"nats-server","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/nats-server?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.12.0"},{"fixed":"2.12.6-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-33219.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}