Resource exhaustion in etcd - CVE-2026-73500
Published: July 24, 2026 / Updated: August 13, 2026
Vulnerability identifier: #VU139353
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2026-73500
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in tlsListener.acceptLoop when handling TCP connections that never complete the TLS handshake. A remote attacker can open many TCP connections and withhold a ClientHello to cause a denial of service.
Each connection spawns a goroutine that blocks indefinitely inside tls.Conn.Handshake() and is tracked in the pending map.
Affected software
etcd
How to mitigate CVE-2026-73500
Install security update from vendor's website.
etcd - addressed in versions 3.5.33, 3.6.14, 3.7.1