CVE-2025-14821 Red Hat CVE debrief

Who should care

System administrators and security teams responsible for managing SSH connections and libssh installations, especially on Windows systems, should be aware of this vulnerability. They should assess their exposure and take necessary steps to mitigate the risk. Additionally, developers and users of libssh should be aware of the insecure default configuration and take steps to secure their installations.

Technical summary

The vulnerability in libssh allows local man-in-the-middle attacks and security downgrades of SSH connections due to an insecure default configuration on Windows systems. The library loads configuration files from the C: etc directory, which can be modified by unprivileged local users. This allows attackers to manipulate trusted host information and compromise SSH communications. The vulnerability has a CVSS score of 7.8 and is considered HIGH severity.

Defensive priority

High priority should be given to patching or mitigating this vulnerability, especially on Windows systems where libssh is used. System administrators and security teams should assess their exposure and take necessary steps to secure their installations.

Recommended defensive actions

• Patch libssh installations to the latest version, which addresses this vulnerability.
• Review and modify the libssh configuration to prevent loading configuration files from untrusted directories.
• Implement additional security measures, such as monitoring and logging, to detect and respond to potential attacks.
• Conduct a thorough risk assessment to identify and prioritize vulnerable systems.
• Develop and implement a remediation plan to address vulnerable systems.

Evidence notes

The CVE-2025-14821 vulnerability in libssh has a CVSS score of 7.8 and is considered HIGH severity. The vulnerability allows local man-in-the-middle attacks and security downgrades of SSH connections due to an insecure default configuration on Windows systems. The library loads configuration files from the C: etc directory, which can be modified by unprivileged local users. The CVE was published on April 7, 2026, and last modified on June 25, 2026.

Official resources