Back-to-back N-able bugs send admins on a patching spree
CVE-2026-86218, a CVSS 10.0 pre-auth RCE in N-able N-central, is being exploited in the wild; Hotfix 4 mitigates it immediately.
N-able disclosed CVE-2026-86218 on September 6, a pre-authentication remote code execution flaw with CVSS 10.0 in its N-central RMM platform, and both N-able and Huntress report it is being exploited in the wild. It follows Huntress's disclosure of an exploit chain combining CVE-2026-86206 and CVE-2026-86207 that bypasses access controls to create unauthorized administrative accounts, investigated after a September 4 compromise of a fully patched customer environment. N-able has applied mitigations to all hosted N-central instances; on-premises customers must upgrade to Hotfix 4 (build 2026.3.1.14) immediately.
CISA Warns of N-able N-central RCE Vulnerability Exploited in the Wild
CISA added CVE-2026-86218, a CVSS 10.0 unauthenticated RCE in N-able N-central RMM, to its KEV catalog; on-premises admins must patch to 2026.3.1.14.
CISA added CVE-2026-86218, a CVSS 10.0 static code injection (CWE-96) enabling unauthenticated RCE in N-able N-central, to the Known Exploited Vulnerabilities catalog on September 8, 2026. The flaw affects all on-premises builds before 2026.3.1.14 across the 2025.4 through 2026.3 release lines; N-able shipped Hotfix 4 for 2026.3 on September 5-6, 2026. Huntress research indicates at least one customer's N-central instance was compromised on September 4, and federal civilian agencies must mitigate by September 11 under BOD 26-04. Hosted environments were patched server-side, but a compromised RMM server can serve as a single point of entry into entire MSP client bases.
N-able ships second N-central hotfix as attackers keep exploiting CVE-2026-18577
N-able shipped a second N-central hotfix as attackers actively exploit authentication bypass CVE-2026-18577, attributed to ransomware group Storm-1175.
N-able released Hotfix 2 (N-central 2026.3.1.10) to counter ongoing exploitation of CVE-2026-18577, an authentication bypass that evades the patch for the earlier CVE-2026-18556; exploitation was first detected on August 1, 2026. Post-exploitation includes using the Take Control feature to reach managed endpoints, registering a Cloudflare tunnel service for persistence, creating a 'veeam' domain account, resetting admin passwords, and disabling Microsoft and Sophos security tooling. Microsoft analysts link the activity to Storm-1175, which now deploys a new StormEncryptor ransomware strain instead of Medusa, often reaching data exfiltration and ransomware within days. Sophos and Huntress expanded the IOCs and warned that partners who patched late should treat environments as potentially compromised.
CISA Warns of SonicWall SMA1000 Vulnerabilities Active Exploitation (CVE-2026-83548 & CVE-2026-83549)
CISA added two actively exploited SonicWall SMA1000 flaws to KEV: pre-auth SSRF CVE-2026-83548 (CVSS 10) and post-auth RCE CVE-2026-83549; patch by September 5.
CISA added CVE-2026-83548 and CVE-2026-83549 to the Known Exploited Vulnerabilities Catalog with a September 5, 2026 patch deadline. CVE-2026-83548 is a critical (CVSS 10.0) pre-authentication SSRF in the SMA1000 Appliance Work Place interface; CVE-2026-83549 is a high (CVSS 7.8) post-authentication OS command injection leading to RCE in the Appliance Management Console. SMA1000 models 6210, 7210, and 8200v running 12.4.3-03453 or 12.5.0-02835 platform-hotfix and older are affected; fixes ship in 12.4.3-03526 and 12.5.0-02952. Qualys customers can detect vulnerable assets via QID 388624.
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.
Acronis Plugin Vulnerability in cPanel and Plesk Exploited in the Wild
Acronis patched CVE-2026-87886 (CVSS 7.8), a local privilege escalation flaw in its cPanel and Plesk backup plugins, exploited in targeted attacks.
Acronis released fixes for CVE-2026-87886 (CVSS 7.8, CWE-276), an insecure file permissions flaw in Linux-based backup components for cPanel & WHM and Plesk that enables local privilege escalation. The vendor observed limited, targeted exploitation in the wild before patches shipped. Fixes are available in Backup plugin for cPanel & WHM 1.9.3 HF3 and Backup extension for Plesk 1.8.11. A local attacker with low privileges could gain elevated access to backup data, control panels, and other customer accounts on shared hosting infrastructure.
Attackers use rogue ScreenConnect clients to spread malware
Attackers deploy rogue ScreenConnect clients that spread VBScript malware to newly connected machines while ConnectWise patches a file-transfer flaw.
ConnectWise confirmed a file transfer flaw in ScreenConnect affecting both Cloud and On-Premise deployments, with a CVE identifier and official fix promised within the week; administrators can mitigate immediately by disabling TransferFiles (or TransferFilesInSession) in each role. Huntress documented incidents where social engineering installs rogue ScreenConnect clients that spawn Windows Script Host processes running four VBScript files (1.vbs-4.vbs), add a WindowsServiceHost registry Run key, and propagate to newly connected endpoints. Payloads enabled host profiling, persistence, additional ScreenConnect installs, tunneling, security-control changes, and cryptocurrency mining. ConnectWise has not confirmed a technical link between the flaw and this campaign.
N-able patches critical N-central zero-day exploited in the wild (CVE-2026-86218)
N-able shipped an emergency hotfix for CVE-2026-86218, a pre-auth RCE zero-day in N-central RMM observed exploited in the wild.
N-able released Hotfix 4 for N-central 2026.3 on September 5 (build 2026.3.1.14), fixing CVE-2026-86218, a critical pre-authenticated remote code execution flaw in its RMM platform popular with MSPs. A private customer notice marked urgent said the zero-day 'has been observed being exploited in the wild,' while the public advisory said there were no confirmed production exploits. Huntress also flagged two high-severity vulnerabilities, CVE-2026-86206 and CVE-2026-86207, which allow authentication bypass and unrestricted access; they were patched the same weekend and were discovered by Rapid7's Stephen Fewer. N-able advised auditing N-central user accounts for unexpected users.
NSA, CISA, FBI, DOE, and EPA Warn of Active AI
Five US agencies warn of active AI-assisted attacks on internet-exposed Siemens S7 PLCs across critical infrastructure, using disguised snap7 scripts for pre-positioning reconnaissance.
NSA, CISA, FBI, DOE, and EPA issued joint advisory CISA AA26-231A warning of an active hacking campaign against Siemens S7-series PLCs, from S7-200 through S7-1500 F-series, across US critical infrastructure. Threat actors use internet scanning services such as Censys and ZoomEye to locate exposed controllers, then perform read operations over S7comm on TCP port 102 using the legitimate snap7.dll and python-snap7 libraries, disguising AI-generated exploitation scripts as monitoring tools. The agencies assess the activity as pre-positioning ahead of possible process disruption, equipment damage, or safety incidents in Energy, Water, Critical Manufacturing, Chemical, Food and Agriculture, and Commercial Facilities sectors.