Microsoft security advisory – September 2026 monthly rollup (AV26-896) – Update 1
Canada's Cyber Centre relays Microsoft's September 2026 rollup; CISA added exploited zero-days CVE-2026-85880 and CVE-2026-81963 to KEV.
Advisory AV26-896 from the Canadian Centre for Cyber Security summarizes Microsoft's September 2026 monthly security rollup, listing affected products across Windows, Office, .NET, Azure, Exchange and SQL Server. It notes Microsoft confirmed CVE-2026-81963 and CVE-2026-85880 have been exploited. On September 8, 2026, CISA added both CVEs to its Known Exploited Vulnerabilities catalog, and administrators are urged to apply the updates.
VectraRAT Malware-as-a-Service Lets Hackers Bypass UAC and Hijack Windows Systems
New VectraRAT malware-as-a-service at $250/month combines RAT capabilities, credential theft, clipboard hijacking, and a UACME-based UAC bypass; 38 victims observed.
VectraRAT is a previously undocumented MaaS platform with a Go-based VectraHub Linux C2 server embedding a Vue3 operator panel and a C++ Windows implant, rented from $250/month and linked to the aliases Vectra and Nyxel. It communicates over TCP port 3308 via a proprietary MessagePack protocol, steals browser and file-based credentials, and abuses UACME method 41 with debug-object handle hijacking via winver.exe and computerdefaults.exe. SOCRadar identified 38 live victim sessions in one week, 48% on corporate Windows editions, with delivery via the Amadey loader and ClickFix pages impersonating TurboTax.
Microsoft releases Windows 10 KB5122878 extended security update
Microsoft shipped Windows 10 ESU update KB5122878, delivering the record September 2026 Patch Tuesday fixes, including patches for two actively exploited zero-days.
Microsoft released KB5122878 for Windows 10 Enterprise LTSC and ESU customers, moving builds 19045/19044 to .7725 with security and bug fixes. The update carries this month's record September 2026 Patch Tuesday set, which fixed 966 Microsoft vulnerabilities including two actively exploited zero-day flaws. It also fixes BitLocker recovery-key prompts and Remote Desktop audio redirection, and updates Secure Boot certificate rollout and Morocco time zone data. Microsoft reports no known issues with the update.