Info Security Magazine23 Mar 2026
CISA Orders US Government to Patch Maximum Severity Cisco Flaw
CISA added CVE-2026-20131 to its KEV catalog as it is being used in ransomware campaigns
Actively exploited vulnerability
CVE-2026-20131: Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability
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.
CISA KEV source
19 Mar 2026 added
22 Mar 2026 remediation due
Affected product
Cisco · Secure Firewall Management Center (FMC)
Known ransomware use: Known
Required action
Follow the source advisory and validate exposure in your environment.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Related Yasna coverage
Recent reporting that mentions CVE-2026-20131.
Bleeping Computer21 Mar 2026
CISA orders feds to patch max-severity Cisco flaw by Sunday
The Cybersecurity and Infrastructure Security Agency (CISA) has ordered federal agencies to patch a maximum-severity vulnerability, CVE-2026-20131, in Cisco Secure Firewall Management Center (FMC) by Sunday, March 22. [...]
The Register19 Mar 2026
Ransomware crims abused Cisco 0-day weeks before disclosure, says Amazon security boss
Interlock's post-exploit toolkit exposed Ransomware criminals exploited CVE-2026-20131, a maximum-severity bug in Cisco Secure Firewall Management Center software, as a zero-day vulnerability more than a month before Cisco patched the hole, according to Amazon security boss CJ Moses.…
The Hacker News19 Mar 2026
Interlock Ransomware Exploits Cisco FMC Zero-Day CVE-2026-20131 for Root Access
Amazon Threat Intelligence is warning of an active Interlock ransomware campaign that's exploiting a recently disclosed critical security flaw in Cisco Secure Firewall Management Center (FMC) Software