{"id":"UBUNTU-CVE-2026-27889","details":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server.  This happens before authentication, and so is exposed to anyone who can connect to the websockets port. Versions 2.11.14 and 2.12.5 contains a fix. A workaround is available. The vulnerability only affects deployments which use WebSockets and which expose the network port to untrusted end-points. If one is able to do so, a defense in depth of restricting either of these will mitigate the attack.","modified":"2026-07-02T18:02:39.680304186Z","published":"2026-03-25T20:16:00Z","upstream":["CVE-2026-27889"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-27889"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-27889"},{"type":"REPORT","url":"https://advisories.nats.io/CVE/secnote-2026-03.txt"},{"type":"REPORT","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-pq2q-rcw4-3hr6"}],"affected":[{"package":{"name":"nats-server","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/nats-server?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.9.19-1build1","2.10.3-1","2.10.4-1","2.10.7-1","2.10.7-1ubuntu0.1","2.10.7-1ubuntu0.2","2.10.7-1ubuntu0.3"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-nats-io-nats-server-dev","binary_version":"2.10.7-1ubuntu0.3"},{"binary_version":"2.10.7-1ubuntu0.3","binary_name":"nats-server"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27889.json"}},{"package":{"name":"nats-server","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/nats-server?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.24-1","2.10.27-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-nats-io-nats-server-dev","binary_version":"2.10.27-1"},{"binary_version":"2.10.27-1","binary_name":"nats-server"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27889.json"}},{"package":{"name":"nats-server","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/nats-server?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.27-1","2.10.27-1build1","2.10.27-1ubuntu0.26.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-nats-io-nats-server-dev","binary_version":"2.10.27-1ubuntu0.26.04.1~esm1"},{"binary_name":"nats-server","binary_version":"2.10.27-1ubuntu0.26.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27889.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}