What is CVE-2026-55653?

CVE-2026-55653 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Double Free. CVSS score: 4.3/10. Published 2026-06-23.

How severe is CVE-2026-55653?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Double Free in Red Hat Enterprise Linux 10

CVE-2026-55653

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 vali…

Vulnerability class: Double Free

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.

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

Weakness classification (CWE)

CWE-415 — Double Free

References

secalert@redhat.com (x_refsource_REDHAT, vdb-entry)
secalert@redhat.com (x_refsource_REDHAT, issue-tracking)

Frequently asked questions

What is CVE-2026-55653?: CVE-2026-55653 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Double Free. CVSS score: 4.3/10. Published 2026-06-23.
How severe is CVE-2026-55653?: Medium severity. CVSS v3 base score is 4.3 out of 10.