What EVULNABLE says
Listed in the CISA KEV catalog, and Confirmed exploitation in the wild.
Out-of-Band / Urgent Remediation
CVE-2026-20131
Cisco — Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability
CISA KEV · in the CISA KEV catalog since 2026-03-19
The priority band answers “how soon”, not “how bad” — see Methodology for what it weighs and where it abstains.
The evidence behind it
| Measure | Value | Source |
|---|---|---|
| CVSS base score | 10.0 | NVD |
| FIRST EPSS | 0.312 (98.2nd pctl) | FIRST |
| Actively exploited | Confirmed | CISA KEV |
| Ransomware campaign use | Known | CISA KEV |
| CISA remediation deadline | 2026-03-22 — Overdue by 6 months | CISA KEV |
What CISA says to do
The primary records
This page is an opinion about urgency. Where it and a source of record disagree, the source of record is the record.
Where this sits
CVE-2026-20131 is one of the entries ranked on the priority feed and in the non-Microsoft advisories.