CVE-2026-55653Openssh: 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
Updated under an hour ago ()
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It affects Red Hat Enterprise Linux 10 and 10 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- Weakness (CWE)
- CWE-415
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Modified
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux | from 0:9.9p1-25.el10_2 not affected | CNA record |
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support redhat:enterprise_linux_eus | from 0:9.9p1-7.el10_0.5 not affected | CNA record |
from 0:8.7p1-38.el9_4.10 not affected | CNA record | |
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support redhat:rhel_eus | from 0:8.7p1-45.el9_6.5 not affected | CNA record |
Red Hat Red Hat Hardened Images redhat:hummingbird | from 10.3p1-6.hum1 not affected | CNA record |
Red Hat Red Hat OpenShift AI 3.0 redhat:openshift_ai | from 1791818590 not affected | CNA record |
Red Hat Red Hat Update Infrastructure 5 redhat:rhui | from 1786435483 not affected | CNA record |
Red Hat Red Hat OpenShift Container Platform 4 redhat:openshift | 4 | CNA record |
openbsd openssh openbsd:openssh | all versions | NVD |
redhat hardened_images redhat:hardened_images | all versions | NVD |
redhat openshift_container_platform redhat:openshift_container_platform | 4.0 | NVD |
redhat enterprise_linux redhat:enterprise_linux | 6.0; 7.0; 8.0; 9.0; 10.0 | NVD |
References
- https://access.redhat.com/errata/RHSA-2026:36759vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:47755vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:47756vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:47757vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:54387vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:58981vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:76748vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:76993vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:80513vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82749vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82750vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82751vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82752vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82753vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82754vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82755vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82756vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82757vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82758vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82759vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82761vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82762vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82763vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82897vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82898vendor-advisory, x-refsource-redhat
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.