Cisco Warns of Ongoing Exploitation of Critical Email Gateway Zero-Day
Cisco Secure Email Gateway zero-day CVE-2026-76461 (CVSS 9.8) is actively exploited for root command execution; CISA added it to KEV.
Cisco disclosed critical zero-day CVE-2026-76461 (CVSS 9.8) in Secure Email Gateway, remotely exploitable without authentication via crafted emails containing malicious SQL statements, leading to arbitrary command execution with root privileges. The flaw affects physical and virtual appliances regardless of configuration and has no workarounds. Cisco PSIRT confirmed active exploitation, and CISA added the CVE to its KEV catalog on September 14 with a federal remediation deadline of September 17. Admins should review mail_logs for suspicious SQL statements such as 'COPY.*TO PROGRAM'.
macOS Screen Sharing Flaw Exploited to Deploy Monero Miners
Dutch NCSC confirms active exploitation of critical macOS Screen Sharing flaw CVE-2026-65400, granting root access and installing Monero miners.
CVE-2026-65400 (CVSS 9.8) is an authentication state-management flaw in macOS's built-in Screen Sharing that lets network attackers authenticate without valid credentials. The Dutch NCSC confirmed active exploitation against systems with port 5900 exposed to the internet; in every documented case attackers obtained root access and installed a Monero cryptocurrency miner. Apple patched the bug in macOS Tahoe 26.6.1, Sequoia 15.7.9, and Sonoma 14.8.9, crediting Alfredo Pesoli of Bynario. A related researcher scan found roughly 40,000 exposed Screen Sharing hosts, and security firm Calif built working exploits for related flaws in about four hours using an AI coding agent.
Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories
Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.
Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.
Cisco confirms CVE-2026-20079 Secure FMC flaw exploited in attacks
Cisco confirmed active exploitation of CVE-2026-20079, a CVSS 10.0 authentication bypass enabling unauthenticated root command execution in Secure FMC; CISA added it to KEV.
Cisco confirmed in August 2026 that CVE-2026-20079 (CVSS 10.0), an unauthenticated authentication bypass in Secure Firewall Management Center, is being actively exploited, allowing remote attackers to execute scripts and commands as root via crafted HTTP requests to the web interface. CISA added the flaw to its Known Exploited Vulnerabilities catalog, ordering federal civilian agencies to patch by September 12, 2026. Shared IOCs, identical hot fixes, and a July 23 log entry suggest CVE-2026-20079 was used alongside the separately exploited static-credential flaw CVE-2026-20316 in the same attacks. Cisco released patches and cloud fixes, warns hot fixes do not remediate already-compromised devices, and says there are no workarounds.