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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-6vch-q96h-7gc3 etcd: `tlsListener.acceptLoop` spawns unbounded handshake goroutines with no deadline
Fixes

Solution

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Workaround

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History

Wed, 12 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title etcd: `tlsListener.acceptLoop` spawns unbounded handshake goroutines with no deadline
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-12T21:22:25.151Z

Reserved: 2026-08-12T19:00:33.736Z

Link: CVE-2026-73500

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-12T22:17:17.290

Modified: 2026-08-12T22:17:17.290

Link: CVE-2026-73500

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses