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
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).
Evidence and details
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-55653
Red Hat Enterprise Linux 10
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 10.0 Extended Update Support
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 8
Source reference: /containers/cna/affected/2/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 8
Source reference: /containers/cna/affected/3/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9
Source reference: /containers/cna/affected/4/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9
Source reference: /containers/cna/affected/5/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
Source reference: /containers/cna/affected/6/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9.6 Extended Update Support
Source reference: /containers/cna/affected/7/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Hardened Images
Source reference: /containers/cna/affected/8/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.0
Source reference: /containers/cna/affected/9/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.0
Source reference: /containers/cna/affected/10/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.0
Source reference: /containers/cna/affected/11/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.0
Source reference: /containers/cna/affected/12/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.0
Source reference: /containers/cna/affected/13/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.2
Source reference: /containers/cna/affected/14/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.2
Source reference: /containers/cna/affected/15/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.2
Source reference: /containers/cna/affected/16/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.2
Source reference: /containers/cna/affected/17/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.2
Source reference: /containers/cna/affected/18/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.2
Source reference: /containers/cna/affected/19/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/20/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/21/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/22/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/23/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/24/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/25/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/26/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.3
Source reference: /containers/cna/affected/27/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/28/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/29/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/30/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/31/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/32/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/33/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/34/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/35/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.4
Source reference: /containers/cna/affected/36/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/37/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/38/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/39/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/40/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/41/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/42/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/43/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/44/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift AI 3.5
Source reference: /containers/cna/affected/45/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Update Infrastructure 5
Source reference: /containers/cna/affected/46/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Update Infrastructure 5
Source reference: /containers/cna/affected/47/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Update Infrastructure 5
Source reference: /containers/cna/affected/48/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Update Infrastructure 5
Source reference: /containers/cna/affected/49/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 6
Source reference: /containers/cna/affected/50/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 7
Source reference: /containers/cna/affected/51/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift Container Platform 4
Source reference: /containers/cna/affected/52/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift Container Platform 4
Source reference: /containers/cna/affected/53/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
- Related CVEs
- CVE-2026-55653
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics