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).
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://access.redhat.com/security/cve/CVE-2026-55653 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2462351 Exploit, Issue Tracking, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 2
- References+1 references (now 49)NVD modified 2026-10-26 04:17
- First seenCVSS 6.5 · openbsd, redhatNVD modified 2026-10-14 20:17
Affected (CPE criteria) 8
cpe:2.3:a:openbsd:openssh:-:*:*:*:*:*:*:*cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:*cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
References 49
- 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/errata/RHSA-2026:76748
- https://access.redhat.com/errata/RHSA-2026:76993
- https://access.redhat.com/errata/RHSA-2026:80513
- https://access.redhat.com/errata/RHSA-2026:82749
- https://access.redhat.com/errata/RHSA-2026:82750
- https://access.redhat.com/errata/RHSA-2026:82751
- https://access.redhat.com/errata/RHSA-2026:82752
- https://access.redhat.com/errata/RHSA-2026:82753
- https://access.redhat.com/errata/RHSA-2026:82754
- https://access.redhat.com/errata/RHSA-2026:82755
- https://access.redhat.com/errata/RHSA-2026:82756
- https://access.redhat.com/errata/RHSA-2026:82757
- https://access.redhat.com/errata/RHSA-2026:82758
- https://access.redhat.com/errata/RHSA-2026:82759
- https://access.redhat.com/errata/RHSA-2026:82761
- https://access.redhat.com/errata/RHSA-2026:82762
- https://access.redhat.com/errata/RHSA-2026:82763
- https://access.redhat.com/errata/RHSA-2026:82897
- https://access.redhat.com/errata/RHSA-2026:82898
- https://access.redhat.com/errata/RHSA-2026:82899
- https://access.redhat.com/errata/RHSA-2026:82900
- https://access.redhat.com/errata/RHSA-2026:82901
- https://access.redhat.com/errata/RHSA-2026:82902
- https://access.redhat.com/errata/RHSA-2026:82903
- https://access.redhat.com/errata/RHSA-2026:82904
- https://access.redhat.com/errata/RHSA-2026:82907
- https://access.redhat.com/errata/RHSA-2026:82908
- https://access.redhat.com/errata/RHSA-2026:82909
- https://access.redhat.com/errata/RHSA-2026:82910
- https://access.redhat.com/errata/RHSA-2026:82912
- https://access.redhat.com/errata/RHSA-2026:82913
- https://access.redhat.com/errata/RHSA-2026:82914
- https://access.redhat.com/errata/RHSA-2026:82915
- https://access.redhat.com/errata/RHSA-2026:82916
- https://access.redhat.com/errata/RHSA-2026:82917
- https://access.redhat.com/errata/RHSA-2026:82918
- https://access.redhat.com/errata/RHSA-2026:82920
- https://access.redhat.com/errata/RHSA-2026:82921
- https://access.redhat.com/errata/RHSA-2026:82922
- https://access.redhat.com/errata/RHSA-2026:82923
- https://access.redhat.com/errata/RHSA-2026:89739
- https://access.redhat.com/security/cve/CVE-2026-55653 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2462351 Exploit, Issue Tracking, Vendor Advisory