Cisco FMC Flaws Exploited to Steal Credentials and Deploy Qilin Ransomware
Three threat clusters including a Sandworm-linked group and Qilin ransomware operators exploit Cisco FMC flaws CVE-2026-20079 and CVE-2026-20316.
Cisco Talos identified three clusters of post-compromise activity exploiting CVE-2026-20079 (CVSS 10.0, unauthenticated web-interface authentication bypass enabling root code execution) and CVE-2026-20316 (CVSS 5.3, low-privilege login exposing sensitive data) in Secure Firewall Management Center. UAT-12197 deployed JSP web shells and a JAR-based command executor to query internal databases for credentials; UAT-11823 used a Netcat reverse shell, configuration-harvesting scripts and a Cyclops Blink variant previously attributed to Russia's Sandworm; UAT-11988 used living-off-the-land FMC tooling for reconnaissance before deploying Qilin ransomware. CISA added CVE-2026-20079 to its KEV catalog, requiring FCEB agencies to patch by September 12, 2026; CVE-2026-20316 was added in late July 2026.