{"id":"CVE-2026-20341","aliases":["EUVD-2026-81110","GHSA-355g-mjpr-92rq"],"status":"published","title":"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\u0026nbsp;root privileges.\r\n\r\nThis 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.\r\nTo exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.","severity":{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00608,"percentile":0.49464,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-502"],"published":"2026-09-16T20:08:28Z","modified":"2026-09-18T04:17:47Z","products":[{"vendor":"cisco","product":"cisco secure firewall management center (fmc)"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20341"},{"url":"https://github.com/advisories/GHSA-355g-mjpr-92rq"}],"sources":{"cve":[{"id":"CVE-2026-20341","title":"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\u0026nbsp;root privileges.\r\n\r\nThis 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.\r\nTo exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.","status":"published","published":"2026-09-16T20:08:28.26Z","modified":"2026-09-18T03:55:58.88Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T13:35:33.380441Z"}],"euvd":[{"id":"EUVD-2026-81110","description":"A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain\u0026nbsp;root privileges.\r\n\r\nThis 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.\r\nTo exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.","status":"published","published":"2026-09-16T20:08:28Z","modified":"2026-09-18T03:55:58Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T17:28:09.684322Z"}],"ghsa":[{"id":"GHSA-355g-mjpr-92rq","title":"A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software...","description":"A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain\u0026nbsp;root privileges.\n\nThis 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.\nTo exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.","status":"published","published":"2026-09-16T21:32:45Z","modified":"2026-09-16T21:32:50Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T15:12:02.095044Z"}],"nvd":[{"id":"CVE-2026-20341","description":"A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain\u0026nbsp;root privileges.\r\n\r\nThis 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.\r\nTo exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.","status":"published","published":"2026-09-16T20:17:24.193Z","modified":"2026-09-18T04:17:47.18Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T14:12:48.630594Z"}]}}