CVE-2026-20131
Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data in Cisco Secure Firewall Management Center (FMC). CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 19 March 2026.
- Product
- Cisco Secure Firewall Management Center (FMC)
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- Known to be used in ransomware
- Vendor advisories
- Sources
- CISA’s catalog, NVD entry
CISA’s description.
Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management contain a deserialization of untrusted data vulnerability in the web-based management interface that could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device.
More from Cisco this year.
- CVE-2026-76418 Unchecked Return Value to NULL Pointer Dereference, added
- CVE-2026-76519 Relative Path Traversal, added
- CVE-2026-76504 Hex Encoding, added
- CVE-2026-76460 Incorrect Use of Privileged APIs, added
- CVE-2026-76461 SQL Injection, added
- CVE-2026-20079 Firewall Management Center Authentication Bypass Using an Alternate Path or Channel, added
- CVE-2026-20349 Heap Inspection, added
- CVE-2026-20316 Secure Firewall Management Center Use of Hard-coded Password, added
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.