CVE-2026-55653EPSS p20.5%

CVE-2026-55653CVE-2026-55653

openbsd / openssh

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).

Scoring

CVSS 4.3 ()
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS0.28% probability of exploitation · percentile 20.5% · 2026-08-08T12:02:54Z
Last modified2026-07-30
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.