CVE-2026-20341
Cisco Secure Firewall Management Center Software sftunnel Deserialization Root Command Execution Vulnerability
Description
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.
Weakness: CWE-502
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Secure Firewall Management Center Check your version | Network & Security Management | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco Secure Firewall Management Center (FMC)
Vendor advisory
cisco-sa-fmc-mulivulns-4PsnFwvx
Cisco Secure Firewall Management Center Software Vulnerabilities
Cisco’s rating: Critical (advisory CVSS 9.1) · Published Sep 16, 2026
Bug IDs: CSCwu16954 , CSCwu24501 , CSCwu27275 , CSCwu36643 , CSCwu42586
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from