VulnerabilityModified
CVE-2026-55653
A malicious SSH server can exploit a double free vulnerability in the Diffie-Hellman Group Exchange (DH-GEX) client path.
MEDIUM 6.5EPSS 0.30%
Does this matter?
Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- EPSS
- 0.30% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-415
- Affected
- openbsd/openssh · redhat/hardened images · redhat/openshift container platform · redhat/enterprise linux
- Source
- secalert@redhat.com
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/errata/RHSA-2026:58981
- https://access.redhat.com/security/cve/CVE-2026-55653Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2462351Exploit, Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.