Vulnerability 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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openbsd | Openssh | - |
| Redhat | Hardened Images | - |
| Redhat | Openshift Container Platform | 4.0 |
| Redhat | Enterprise Linux | 6.0 |
Related Weaknesses (CWE)
References
- https://access.redhat.com/errata/RHSA-2026:36759
- https://access.redhat.com/errata/RHSA-2026:47755
- https://access.redhat.com/errata/RHSA-2026:47756
- https://access.redhat.com/errata/RHSA-2026:47757
- https://access.redhat.com/errata/RHSA-2026:54387
- https://access.redhat.com/security/cve/CVE-2026-55653Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2462351ExploitIssue TrackingVendor Advisory
FAQ
What is CVE-2026-55653?
CVE-2026-55653 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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 Proc...
How severe is CVE-2026-55653?
CVE-2026-55653 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55653?
Check the references section above for vendor advisories and patch information. Affected products include: Openbsd Openssh, Redhat Hardened Images, Redhat Openshift Container Platform, Redhat Enterprise Linux.