Week in review: Linux rootkit deployed on F5 BIG-IP APM devices, Cisco FMC bugs exploited
Weekly roundup: Cisco FMC and N-able N-central zero-days exploited in the wild, MikroTik RouterOS hijacks, Microsoft Patch Tuesday ships two exploited zero-days.
State-sponsored and financially-motivated attackers are actively exploiting CVE-2026-20079, a critical authentication bypass in Cisco Secure Firewall Management Center (FMC), alongside CVE-2026-20316. N-able issued an emergency hotfix for CVE-2026-86218, a critical pre-auth RCE in the N-central RMM platform exploited in the wild. CERT Polska disclosed six RouterOS vulnerabilities being chained to hijack internet-exposed MikroTik devices. Microsoft's September 2026 Patch Tuesday shipped a record patch count including two zero-days, while roughly 67,000 Trezor customers faced phishing after a shipping-partner breach and researchers privately disclosed a zero-click WeChat worm to Tencent.
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.
Hackers Drain $320 Million From Liquid Network, Then Return Most of It
Hackers exploited an Elements bug to drain about 4,000 BTC (~$320M) from Liquid Network's federation wallet, then returned 3,400 BTC after Blockstream patched.
An attacker drained roughly 4,000 of 4,200 BTC (~$320M) from Bitcoin's Liquid Network federation wallet on September 6 by exploiting a bug in Elements, the open-source code powering the sidechain, which allowed unbacked L-BTC tokens that were redeemed for real Bitcoin through SideSwap's authorized peg-out mechanism. The self-described white-hat attackers negotiated publicly via OP_RETURN on-chain messages, demanding the bridge nodes be patched before returning 3,400 BTC (~$262.6M) and keeping about 598 BTC (~$47M). Blockstream confirmed the affected bridge nodes were patched; the network remains paused while federation members complete security work, and experts debate whether the act legally constitutes extortion.
Liquid Hackers Return 3,400 Bitcoin Taken via Elements Bug, Still Holding $47M in BTC
Hackers exploited an Elements bug to take ~4,000 BTC from Liquid Network, returned 3,400 BTC (~$265M), and still hold ~598.5 BTC (~$47M).
Attackers exploited a bug in Elements, the software behind Blockstream's Liquid Network Bitcoin sidechain, to create L-BTC and withdraw roughly 4,000 BTC (about $320 million) via SideSwap's Peg-out Authorization Key, roughly 95% of Liquid's reported reserves. They returned 3,400 BTC (about $265 million at ~$78,000 per BTC) to the federation address on September 7, keeping about 598.5 BTC (roughly $47 million). The group called itself white hats, demanded node patches before returning funds, and negotiated via on-chain and PGP-encrypted messages; Ledger CTO Charles Guillemet characterized the arrangement as extortion. Blockstream says the peg-out key and other keys were not compromised, updated software is deployed, and the network remains paused pending a coordinated restart.