CVE-2026-55653: Openssh: double free in red hat enterprise linux versions of openssh dh-gex client path during fips known-group validation leads to client-side denial of service

Overview

Severity

Medium (CVSS 4.3)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

Exploit Status

Not Exploited

Patch Tuesday

2026-Jun

Released

2026-06-27

Last Updated

2026-09-25

EPSS Score

0.51% (percentile: 40.8%)

Affected Products (4)

Other

• 21710-17084
• 21837-17084
• 21261-17084
• 21499-17084

Revision History

• 2026-06-27: Information published.
• 2026-06-28: Information published.
• 2026-08-13: Information published.
• 2026-09-09: Information published.
• 2026-09-25: Information published.