CVE-2026-73500
etcd: `tlsListener.acceptLoop` spawns unbounded handshake goroutines with no deadline
Reported by github_m · Published August 12, 2026
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.
Fixed versions
Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.
| Package | Ecosystem | Fixed in |
|---|---|---|
| loki-3.7 | Wolfi | 3.7.7-r4, 3.7.6-r2 |
| loki-3.5 | Chainguard | 3.5.12-r19 |
| cert-manager-1.20 | Wolfi | 1.20.3-r18, 1.20.3-r11 |
| kine | Wolfi | 0.16.4-r1 |
| hubble | Wolfi | 1.19.4-r13 |
| kyverno-1.17 | Wolfi | 1.17.2-r35, 1.17.2-r30 |
| loki-3.7 | Chainguard | 3.7.7-r4, 3.7.6-r2 |
| cert-manager-1.20 | Chainguard | 1.20.3-r18, 1.20.3-r11 |
| external-dns-0.21 | Wolfi | 0.21.0-r19 |
| cilium-cli | Chainguard | 0.19.7-r3 |
| minio | Wolfi | 0.20260717.120751-r8 |
| kube-conformance-1.35 | Chainguard | 1.35.8-r4 |
9 more packages have a fixed version. See every fix in Lookup.
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| etcd-io | etcd | < 3.5.33, >= 3.6.0, < 3.6.14, >= 3.7.0-alpha.0, < 3.7.1 |
| wolfi | loki-3.7 | 0, 0 |
| chainguard | chartmuseum | * |
| chainguard | kcp-fips-0.31 | * |
| chainguard | loki-3.5 | 0 |
| wolfi | cert-manager-1.20 | 0, 0 |
| wolfi | kine | 0 |
| wolfi | hubble | 0 |
| chainguard | node-feature-discovery-fips-0.17 | * |
| wolfi | kyverno-1.17 | 0, 0 |
| wolfi | grafana-12.4 | * |
| chainguard | grafana-mimir-3.0 | * |
| chainguard | vault-2.0 | * |
| wolfi | datadog-agent-7.78 | * |
| chainguard | loki-3.7 | 0, 0 |
| chainguard | cloud-provider-azure-1.32 | * |
| chainguard | eks-distro-1.31 | * |
| chainguard | teleport-18 | * |
| chainguard | cert-manager-1.20 | 0, 0 |
| chainguard | grafana-mimir-fips-2.17 | * |
…and 480 more
Timeline
- Aug 12, 2026 CVE Published
- Aug 13, 2026 Coalition ESS Score
- Aug 15, 2026 Security Advisory (2 in total, the first dated here)
- Aug 24, 2026 EPSS Score (26 in total, the first dated here)
- Oct 27, 2026 Distribution Patch
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2026-73500
vulnetix vdb fixes CVE-2026-73500Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
"https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-73500/fixes/registry"The Community plan is free and allows 50 queries a day. Get a free API key · API quickstart
References
- https://github.com/etcd-io/etcd/security/advisories/GHSA-6vch-q96h-7gc3 x_refsource_CONFIRM
- https://github.com/etcd-io/etcd/pull/22130 x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/2e07efce9745004eb4773cffaada9b5cdf77cff2 x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/89ff6d50796049d4f1136915ba21504b76e7e372 x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/8e4dd0679a2c6b095d2a32a749fda2521c7809a3 x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/f73cba7d920019f91a1ea1f6697833e42731f057 x_refsource_MISC
- https://github.com/etcd-io/etcd/releases/tag/v3.5.33 x_refsource_MISC
- https://github.com/etcd-io/etcd/releases/tag/v3.6.14 x_refsource_MISC
- https://github.com/etcd-io/etcd/releases/tag/v3.7.1 x_refsource_MISC