{"id":"CVE-2026-55653","title":"A flaw was found in OpenSSH","summary":"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 va…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","cwe":["CWE-415"],"vendor":"openbsd","product":"openssh","affected":["openssh","hardened_images","openshift_container_platform = 4.0","enterprise_linux = 6.0","enterprise_linux = 7.0","enterprise_linux = 8.0","enterprise_linux = 9.0","enterprise_linux = 10.0"],"published":"2026-06-23","updated":"2026-08-24","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55653","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:36759","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:47755","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:47756","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:47757","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:54387","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-55653","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2462351","label":"secalert@redhat.com"}],"tags":["nvd"],"epss":0.00296,"epssPercentile":0.22539,"ingestedAt":"2026-08-24T13:03:31.720Z","slug":"CVE-2026-55653","body":"## Overview\n\nA 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).\n\n## Affected\n\n- `openssh`\n- `hardened_images`\n- `openshift_container_platform = 4.0`\n- `enterprise_linux = 6.0`\n- `enterprise_linux = 7.0`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n- `enterprise_linux = 10.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}