CVE Catalog

CVE-2026-20341

CriticalCVSS 9.1
Published: Updated: Translated: NVD NIST

Summary

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain root privileges. This is due to unsecured deserialization of untrusted data over the sftunnel management connection. An attacker can send crafted sftunnel RPCs to gain root privileges on the device and its high-availability peer. Valid administrative credentials on a managed Cisco FTD device are required.

Risk Assessment

Gaining root privileges on FMC and its peer could lead to full compromise of the security management system, allowing the attacker to manipulate security rules and configurations.

Recommendation

Apply security updates from Cisco for Secure FMC Software. Restrict access to the sftunnel protocol and monitor inter-device communication.

Other vulnerabilities in Cisco Secure FMC Software

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Original NVD description (English source)

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain root privileges. This vulnerability is due to unsecured deserialization of untrusted data over the sftunnel management connection. An attacker could exploit this vulnerability by sending crafted sftunnel remote procedure calls (RPCs). A successful exploit could allow the attacker to gain root privileges on a device that is running Cisco Secure FMC Software and its high-availability peer. To exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS