{"id":"UBUNTU-CVE-2026-73500","details":"etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.5.33, 3.6.14, and 3.7.1, a network attacker who can reach an etcd TLS listener can open many TCP connections and never send a ClientHello. In client/pkg/transport/listener_tls.go, each connection handled by tlsListener.acceptLoop spawns a goroutine that blocks indefinitely inside tls.Conn.Handshake() and remains tracked in the pending map. Unbounded goroutine and map growth can exhaust memory in the etcd process, causing loss of availability for the cluster and, when etcd backs Kubernetes, the control plane. This issue is fixed in versions 3.5.33, 3.6.14, and 3.7.1.","modified":"2026-08-19T11:11:14Z","published":"2026-08-12T22:17:00Z","upstream":["CVE-2026-73500"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-73500"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-73500"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/security/advisories/GHSA-6vch-q96h-7gc3"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/pull/22130"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/commit/2e07efce9745004eb4773cffaada9b5cdf77cff2"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/commit/89ff6d50796049d4f1136915ba21504b76e7e372"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/commit/8e4dd0679a2c6b095d2a32a749fda2521c7809a3"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/commit/f73cba7d920019f91a1ea1f6697833e42731f057"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/releases/tag/v3.5.33"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/releases/tag/v3.6.14"},{"type":"REPORT","url":"https://github.com/etcd-io/etcd/releases/tag/v3.7.1"}],"affected":[{"package":{"name":"etcd","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/etcd?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.0+dfsg-2","2.2.1+dfsg-1","2.2.2+dfsg-1","2.2.2+dfsg-2","2.2.3+dfsg-1","2.2.5+dfsg-1","2.2.5+dfsg-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"etcd","binary_version":"2.2.5+dfsg-1ubuntu1"},{"binary_name":"golang-etcd-server-dev","binary_version":"2.2.5+dfsg-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73500.json"}},{"package":{"name":"etcd","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.0-1","3.2.9+dfsg-2","3.2.9+dfsg-3","3.2.17+dfsg-1","3.2.17+dfsg-1ubuntu0.1~esm1","3.2.17+dfsg-1ubuntu0.1","3.2.17+dfsg-1ubuntu0.1+esm1","3.2.17+dfsg-1ubuntu0.1+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"etcd","binary_version":"3.2.17+dfsg-1ubuntu0.1+esm2"},{"binary_name":"etcd-client","binary_version":"3.2.17+dfsg-1ubuntu0.1+esm2"},{"binary_name":"etcd-server","binary_version":"3.2.17+dfsg-1ubuntu0.1+esm2"},{"binary_name":"golang-etcd-server-dev","binary_version":"3.2.17+dfsg-1ubuntu0.1+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73500.json"}},{"package":{"name":"etcd","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.26+dfsg-3","3.2.26+dfsg-4","3.2.26+dfsg-6","3.2.26+dfsg-6ubuntu0.1","3.2.26+dfsg-6ubuntu0.2","3.2.26+dfsg-6ubuntu0.2+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.2.26+dfsg-6ubuntu0.2+esm1","binary_name":"etcd"},{"binary_version":"3.2.26+dfsg-6ubuntu0.2+esm1","binary_name":"etcd-client"},{"binary_name":"etcd-server","binary_version":"3.2.26+dfsg-6ubuntu0.2+esm1"},{"binary_name":"golang-etcd-server-dev","binary_version":"3.2.26+dfsg-6ubuntu0.2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73500.json"}},{"package":{"name":"etcd","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.25+dfsg-6","3.3.25+dfsg-7","3.3.25+dfsg-7ubuntu0.22.04.1","3.3.25+dfsg-7ubuntu0.22.04.1+esm1","3.3.25+dfsg-7ubuntu0.22.04.2","3.3.25+dfsg-7ubuntu0.22.04.2+esm1","3.3.25+dfsg-7ubuntu0.22.04.2+esm2","3.3.25+dfsg-7ubuntu0.22.04.2+esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"etcd","binary_version":"3.3.25+dfsg-7ubuntu0.22.04.2+esm3"},{"binary_name":"etcd-client","binary_version":"3.3.25+dfsg-7ubuntu0.22.04.2+esm3"},{"binary_name":"etcd-server","binary_version":"3.3.25+dfsg-7ubuntu0.22.04.2+esm3"},{"binary_version":"3.3.25+dfsg-7ubuntu0.22.04.2+esm3","binary_name":"golang-etcd-server-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73500.json"}},{"package":{"name":"etcd","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.23-4ubuntu2","3.4.30-1","3.4.30-1build1","3.4.30-1ubuntu0.24.04.1","3.4.30-1ubuntu0.24.04.2","3.4.30-1ubuntu0.24.04.2+esm1","3.4.30-1ubuntu0.24.04.3","3.4.30-1ubuntu0.24.04.3+esm1","3.4.30-1ubuntu0.24.04.3+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"etcd-client","binary_version":"3.4.30-1ubuntu0.24.04.3+esm2"},{"binary_name":"etcd-server","binary_version":"3.4.30-1ubuntu0.24.04.3+esm2"},{"binary_name":"golang-etcd-server-dev","binary_v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