Resource exhaustion in etcd - #VU139353
Published: July 24, 2026
Vulnerability identifier: #VU139353
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: CoreOS
Affected software:
etcd
etcd
Detailed vulnerability description
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.
Remediation
Install security update from vendor's website.