High
etcd — security advisory
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.
- Products
- etcd
- Affected 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, 3.1.0-1, 3.2.17+dfsg-1, 3.2.17+dfsg-1ubuntu0.1, 3.2.17+dfsg-1ubuntu0.1+esm1, 3.2.17+dfsg-1ubuntu0.1+esm2, 3.2.17+dfsg-1ubuntu0.1~esm1, 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, 3.2.9+dfsg-2, 3.2.9+dfsg-3, 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, 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, 3.5.16-10, 3.5.16-10ubuntu0.26.04.1~esm1, 3.5.16-4, 3.5.30-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-73500
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:16 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-73500
etcd
Fixed versions: Not specified
etcd
Fixed versions: Not specified
etcd
Fixed versions: Not specified
etcd
Fixed versions: Not specified
etcd
Fixed versions: Not specified
etcd
Fixed versions: Not specified
etcd
Fixed versions: Not specified
Complete source record
{
"id": "2fe28a9e8b51f415a1275afe8318a714b44156eaf79443dd75f5d418dc1a983e",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-73500",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-73500",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2026-73500",
"products": [
{
"name": {
"value": "etcd",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.2.0+dfsg-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.1+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.2+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.2+dfsg-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.3+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.5+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.5+dfsg-1ubuntu1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
},
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"affected_versions": [
{
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"evidence": "/affected/1/versions"
},
{
"value": "3.2.9+dfsg-2",
"evidence": "/affected/1/versions"
},
{
"value": "3.2.9+dfsg-3",
"evidence": "/affected/1/versions"
},
{
"value": "3.2.17+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.2.17+dfsg-1ubuntu0.1~esm1",
"evidence": "/affected/1/versions"
},
{
"value": "3.2.17+dfsg-1ubuntu0.1",
"evidence": "/affected/1/versions"
},
{
"value": "3.2.17+dfsg-1ubuntu0.1+esm1",
"evidence": "/affected/1/versions"
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{
"value": "3.2.17+dfsg-1ubuntu0.1+esm2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
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"evidence": "/affected/2/package/name"
},
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{
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"evidence": "/affected/2/versions"
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{
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"evidence": "/affected/2/versions"
},
{
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"evidence": "/affected/2/versions"
},
{
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"evidence": "/affected/2/versions"
},
{
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"evidence": "/affected/2/versions"
},
{
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"evidence": "/affected/2/versions"
}
]
},
{
"name": {
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"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.3.25+dfsg-6",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7ubuntu0.22.04.1",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7ubuntu0.22.04.1+esm1",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7ubuntu0.22.04.2",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7ubuntu0.22.04.2+esm1",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7ubuntu0.22.04.2+esm2",
"evidence": "/affected/3/versions"
},
{
"value": "3.3.25+dfsg-7ubuntu0.22.04.2+esm3",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "etcd",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.4.23-4ubuntu2",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1build1",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1ubuntu0.24.04.1",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1ubuntu0.24.04.2",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1ubuntu0.24.04.2+esm1",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1ubuntu0.24.04.3",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1ubuntu0.24.04.3+esm1",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.30-1ubuntu0.24.04.3+esm2",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "etcd",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.5.16-10",
"evidence": "/affected/5/versions"
},
{
"value": "3.5.30-2",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "etcd",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.5.16-4",
"evidence": "/affected/6/versions"
},
{
"value": "3.5.16-10",
"evidence": "/affected/6/versions"
},
{
"value": "3.5.16-10ubuntu0.26.04.1~esm1",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-73500",
"aliases": [
"UBUNTU-CVE-2026-73500"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
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{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
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"ecosystem": "Ubuntu:16.04:LTS"
},
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"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"
],
"database_specific": {
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},
"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"
}
]
}
},
{
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{
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],
"package": {
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"purl": "pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"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"
],
"database_specific": {
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},
"ecosystem_specific": {
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{
"binary_name": "etcd-client",
"binary_version": "3.2.17+dfsg-1ubuntu0.1+esm2"
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{
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},
"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"
],
"database_specific": {
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},
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{
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},
{
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{
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{
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],
"package": {
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"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"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"
],
"database_specific": {
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},
"ecosystem_specific": {
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{
"binary_name": "etcd",
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},
{
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"binary_version": "3.3.25+dfsg-7ubuntu0.22.04.2+esm3"
},
{
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},
{
"binary_name": "golang-etcd-server-dev",
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{
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}
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],
"package": {
"name": "etcd",
"purl": "pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Fnoble",
"ecosystem": "Ubuntu:Pro:24.04:LTS"
},
"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",
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"3.4.30-1ubuntu0.24.04.3+esm2"
],
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},
"ecosystem_specific": {
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{
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{
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],
"package": {
"name": "etcd",
"purl": "pkg:deb/ubuntu/etcd?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"3.5.16-10",
"3.5.30-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73500.json"
},
"ecosystem_specific": {
"binaries": [
{
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{
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},
{
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{
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}
]
}
],
"package": {
"name": "etcd",
"purl": "pkg:deb/ubuntu/etcd?arch=source&distro=esm-apps%2Fresolute",
"ecosystem": "Ubuntu:Pro:26.04:LTS"
},
"versions": [
"3.5.16-4",
"3.5.16-10",
"3.5.16-10ubuntu0.26.04.1~esm1"
],
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"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73500.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "etcd-client",
"binary_version": "3.5.16-10ubuntu0.26.04.1~esm1"
},
{
"binary_name": "etcd-server",
"binary_version": "3.5.16-10ubuntu0.26.04.1~esm1"
},
{
"binary_name": "golang-etcd-server-dev",
"binary_version": "3.5.16-10ubuntu0.26.04.1~esm1"
}
]
}
}
],
"modified": "2026-10-17T13:01:03.644774834Z",
"provider": "osv",
"upstream": [
"CVE-2026-73500"
],
"references": [
"https://ubuntu.com/security/CVE-2026-73500",
"https://www.cve.org/CVERecord?id=CVE-2026-73500",
"https://github.com/etcd-io/etcd/security/advisories/GHSA-6vch-q96h-7gc3",
"https://github.com/etcd-io/etcd/pull/22130",
"https://github.com/etcd-io/etcd/commit/2e07efce9745004eb4773cffaada9b5cdf77cff2",
"https://github.com/etcd-io/etcd/commit/89ff6d50796049d4f1136915ba21504b76e7e372",
"https://github.com/etcd-io/etcd/commit/8e4dd0679a2c6b095d2a32a749fda2521c7809a3",
"https://github.com/etcd-io/etcd/commit/f73cba7d920019f91a1ea1f6697833e42731f057",
"https://github.com/etcd-io/etcd/releases/tag/v3.5.33",
"https://github.com/etcd-io/etcd/releases/tag/v3.6.14",
"https://github.com/etcd-io/etcd/releases/tag/v3.7.1"
]
},
"related_cves": [
{
"value": "CVE-2026-73500",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360912,
"published_at": "2026-08-12T22:17:00+00:00"
}