PT-2026-51471 · Red Hat · Red Hat Enterprise Linux 10+6

Published 2026-06-23 · Updated 2026-06-23 · CVE-2026-55653

Mitre

CVSS v3.1

4.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

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).

Fix

Double Free

Weakness Enumeration

CWE-415

Related Identifiers

CVE-2026-55653

Affected Products

Red Hat Enterprise Linux 10

Red Hat Enterprise Linux 6

Red Hat Enterprise Linux 7

Red Hat Enterprise Linux 8

Red Hat Enterprise Linux 9

Red Hat Hardened Images

Red Hat Openshift Container Platform 4

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-55653 · Security Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2462351 · Note
• https://access.redhat.com/security/cve/CVE-2026-55653 · Note