CVE-2026-55653
MEDIUMRed Hat Enterprise Linux OpenSSH DH-GEX Client - Double Free Denial of Service
Title source: manualDescription
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).
References (3)
Core 3
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry
x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-55653
Issue Tracking, X_Refsource_Redhat issue-tracking
x_refsource_redhat
RHBZ#2462351
https://bugzilla.redhat.com/show_bug.cgi?id=2462351
Vendor Advisory vendor-advisory
x_refsource_redhat
RHSA-2026:36759
https://access.redhat.com/errata/RHSA-2026:36759
Scores
CVSS v3
4.3
EPSS
0.0024
EPSS Percentile
15.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-415
Status
published
Products (16)
openbsd/openssh
Red Hat/Red Hat Enterprise Linux 10
Red Hat/Red Hat Enterprise Linux 6
Red Hat/Red Hat Enterprise Linux 7
Red Hat/Red Hat Enterprise Linux 8
Red Hat/Red Hat Enterprise Linux 9
Red Hat/Red Hat Hardened Images
Red Hat/Red Hat Hardened Images
10.3p1-6.hum1
Red Hat/Red Hat OpenShift Container Platform 4
redhat/enterprise_linux
6.0
... and 6 more
Published
Jun 23, 2026
Tracked Since
Jun 23, 2026