CVE-2026-55653

MEDIUM EPSS 10.2%

Published Jun 23, 20261w ago · Modified Jun 23, 20261w ago

4.3 CVSS 3.1

Medium

Published Jun 23, 2026 1w ago

Last Modified Jun 23, 2026 1w ago

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).

CVSS Details

Base Score

4.3

Exploitability

2.8

Impact

1.4

Vector string

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

Attack Vector Network

Attack Complexity Low

Privileges Required None

User Interaction Required

Scope Unchanged

Confidentiality None

Integrity None

Availability Low

Threat Intelligence

EPSS Exploit Probability

10.2% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-415

References 2

access.redhat.com https://access.redhat.com/security/cve/CVE-2026-55653
bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=2462351

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.