Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| etcd-io | etcd | < 3.5.33, >= 3.6.0, < 3.6.14, >= 3.7.0-alpha.0, < 3.7.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | etcd | No fix yet | — |
| Debian 13 | etcd | No fix yet | — |
| Debian 12 | etcd | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | etcd | No fix yet | — |
| Ubuntu 16.04 LTS | etcd | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | etcd | No fix yet | — |
| Ubuntu Pro 24.04 LTS | etcd | No fix yet | — |
| Ubuntu Pro 22.04 LTS | etcd | No fix yet | — |
| Ubuntu Pro 20.04 LTS | etcd | No fix yet | — |
| Ubuntu Pro 18.04 LTS | etcd | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | etcd | 3.7.1-0.1.hum1 | RHSA-2026:44868 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | govulncheck-vulndb | 0.0.20260827T195228-160000.1.1 | SUSE-SU-2026:23625-1 |
| SLES 16.0 | govulncheck-vulndb | 0.0.20260827T195228-160000.1.1 | SUSE-SU-2026:23625-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260827T195228-160000.1.1 | openSUSE-SU-2026:21761-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | cert-manager | 1.12.15-12 | — |
| Azure Linux 3 | cloud-provider-kubevirt | 0.5.1-7 | — |
| Azure Linux 3 | flannel | 0.24.2-31 | — |
| Azure Linux 3 | keda | 2.14.1-18 | — |
| Azure Linux 3 | kube-vip-cloud-provider | 0.0.10-8 | — |
| Azure Linux 3 | kubernetes | 1.30.10-29 | — |
| Azure Linux 3 | prometheus-adapter | 0.12.0-9 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | cert-manager-1.20 +1 | 1.20.3-r11 | — |
| Wolfi rolling | cert-manager-1.20-crds +1 | 1.20.3-r18 | — |
| Wolfi rolling | cilium-1.19 +4 | 1.19.7-r1 | — |
| Wolfi rolling | cilium-cli | 0.19.7-r3 | — |
| Wolfi rolling | dapr-daprd-1.17 +1 | 1.17.13-r1 | — |
| Wolfi rolling | datadog-agent-7.79 | No fix yet | — |
| Wolfi rolling | external-dns-0.21 | 0.21.0-r19 | — |
| Wolfi rolling | grafana-mimir-3.1-metaconvert-3.1 | 3.1.5-r0 | — |
| Wolfi rolling | hubble | 1.19.4-r13 | — |
| Wolfi rolling | kine | 0.16.4-r1 | — |
| Wolfi rolling | kots | 1.131.3-r1 | — |
| Wolfi rolling | kubeadm-1.34 +6 | 1.34.11-r2 | — |
| Wolfi rolling | kubeadm-1.35 +6 | 1.35.8-r1 | — |
| Wolfi rolling | kubeadm-1.36 +6 | 1.36.4-r2 | — |
| Wolfi rolling | kubectl-bash-completion-1.35 +3 | 1.35.8-r6 | — |
| Wolfi rolling | kyverno-1.17 | 1.17.2-r35 | — |
| Wolfi rolling | kyverno-cli-1.17 | 1.17.2-r30 | — |
| Wolfi rolling | kyverno-cli-1.18 | 1.18.2-r9 | — |
| Wolfi rolling | kyverno-init-container-1.18 | 1.18.2-r15 | — |
| Wolfi rolling | loki-3.6 +3 | 3.6.16-r0 | — |
| Wolfi rolling | loki-3.7 +2 | 3.7.6-r2 | — |
| Wolfi rolling | minio | 0.20260717.120751-r8 | — |
| Wolfi rolling | ruby3.3-fluent-plugin-grafana-loki-3.7 | 3.7.7-r4 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | go.etcd.io/etcd/client/pkg/v3 | < 3.5.33 · >= 3.6.0, < 3.6.14 · >= 3.7.0-alpha.0, < 3.7.1 | 3.5.33, 3.6.14, 3.7.1 | GO-2026-6107 |
| Go | go.etcd.io/etcd/v3 | >= 3.7.0-alpha.0, < 3.7.1 | 3.7.1 | GHSA-6vch-q96h-7gc3 |
| Go | go.etcd.io/etcd/v3 | >= 3.6.0, < 3.6.14 | 3.6.14 | GHSA-6vch-q96h-7gc3 |
| Go | go.etcd.io/etcd/v3 | < 3.5.33 | 3.5.33 | GHSA-6vch-q96h-7gc3 |
Advisories 4
- WID-SEC-2026-2825 etcd: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 26, 2026
- RHSA-2026:44868 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- SUSE-SU-2026:23625-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Sep 29, 2026
- openSUSE-SU-2026:21761-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Sep 9, 2026
References
- 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