CVE-2026-20242 Cisco Secure Firewall Management Center - Remote Code Execution & Privilege Escalation

Cisco Secure Firewall Management Center contains an insecure deserialization vulnerability caused by processing user-supplied Java byte streams from hosts in the external database access list, letting unauthenticated remote attackers execute arbitrary commands as root, exploit requires attacker control of a host in the external database access list.

CVSS base score 9.8 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.64% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Remote Code Execution
Impact
Remote Code Execution, Privilege Escalation
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
16 September 2026
Updated
15 October 2026
Weakness
CWE-502

Vendor fix

Update to the latest available version of Cisco Secure Firewall Management Center.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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