{"action":"Upgrade github.com/nats-io/nats-server/v2 to 2.11.12 or later.","affected":[{"fixed":"2.11.12","introduced":"0"},{"fixed":"2.12.3","introduced":"2.12.0-RC.1"}],"component":"github.com/nats-io/nats-server/v2","cve_ids":["CVE-2026-27571"],"ecosystem":"Go","epss":0.00821,"exploited":false,"fixed_versions":["2.11.12","2.12.3"],"ghsa_id":"GHSA-qrvq-68c2-7grw","id":"tcs_01M5KGECJDMJZ65QQ49VT2MVWW","modified_at":"2026-03-02T12:17:25.753901Z","published_at":"2026-02-25T23:07:04Z","references":["https://osv.dev/vulnerability/GO-2026-4533","https://github.com/nats-io/nats-server/security/advisories/GHSA-qrvq-68c2-7grw","https://github.com/nats-io/nats-server/commit/f77fb7c4535e6727cc1a2899cd8e6bbdd8ba2017","https://github.com/nats-io/nats-server/releases/tag/v2.11.12","https://github.com/nats-io/nats-server/releases/tag/v2.12.3"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2026-4533#Go/github.com/nats-io/nats-server/v2","url":"https://osv.dev/vulnerability/GO-2026-4533"}],"summary":"nats-server websockets are vulnerable to pre-auth memory DoS in github.com/nats-io/nats-server"}