jwa7470/cve-2026-20131-post-incident-written-reportPost-incident report on CVE-2026-20131 (CVSS 10.0), a Cisco FMC insecure deserialization vulnerability exploited by Interlock ransomware. Details root-cause analysis, lateral movement tactics, and emergency containment strategies.
This post-incident report analyzes the exploitation of CVE-2026-20131, a critical zero-day unauthenticated Remote Code Execution (RCE) vulnerability in Cisco Secure Firewall Management Center (FMC). The document covers the initial intrusion vector via Java object deserialization (CWE-502), threat actor tactics used by the Interlock ransomware group, network enumeration workflows, and forensic timelines. It details root cause findings, lessons learned regarding network segmentation, and a phased remediation strategy covering immediate patching, account audits, and Zero Trust implementations.
