CVE-2026-59850 Red Hat CVE debrief

Who should care

Users of libssh, system administrators, security teams, and vulnerability management teams should be aware of this vulnerability and take steps to mitigate it. They should review libssh configurations, apply patches or updates provided by the vendor, and monitor for suspicious activity.

Technical summary

The vulnerability exists in libssh, a widely-used SSH library. When data packets are processed after a channel is closed, channel data callbacks can be invoked after the associated data has already been freed. This can lead to crashes or possible use-after-free conditions. Affected systems may experience disruptions or potential security risks if not properly mitigated. Users should review libssh configurations and apply patches or updates provided by the vendor to address this issue. The flaw can potentially impact confidentiality, integrity, or availability, emphasizing the need for prompt mitigation. Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up. Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.

Defensive priority

Medium priority due to the potential for crashes or use-after-free conditions, which could impact system stability or security.

Recommended defensive actions

• Apply patches or updates provided by the vendor
• Review and update libssh configurations
• Monitor for suspicious activity
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions and retest remediated assets
• Perform an asset inventory to identify potentially affected systems

Evidence notes

The CVE record was published on 2026-07-21T15:16:37.773Z and was last modified on 2026-07-22T20:17:04.693Z. The NVD entry is currently Undergoing Analysis. Affected product deployments may exist in managed environments. Owners should confirm and review official advisories for scope, severity, and guidance. Defenders should verify exposed assets and track exceptions.

Official resources