Double Free The advisory has been revoked - it doesn't affect any version of package rhcos (opens in a new tab)

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Snyk IDSNYK-RHEL9-RHCOS-17426357
published23 Jun 2026
disclosed22 Jun 2026

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Introduced: 22 Jun 2026

CVE-2026-55653 (opens in a new tab) CWE-415 (opens in a new tab)

Amendment

The Red Hat security team deemed this advisory irrelevant for RHEL:9.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rhcos package and not the rhcos package as distributed by RHEL.

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).