CVE-2026-55653
MEDIUM
NVD
CVSS Score
4.3
Severity
MEDIUM
Published
Jun 23, 2026
Vendor
unknown
Description
A flaw was found in OpenSSH. A malicious SSH server can exploit a double free vulnerability in the Diffie-Hellman Group Exchange (DH-GEX) client path. This occurs during FIPS (Federal Information Processing Standards) mode known-group validation when the client processes attacker-controlled DH-GEX group parameters. Successful exploitation leads to client-side process termination, resulting in a Denial of Service (DoS).