Microsoft’s September 2026 Patch Tuesday addresses 964 CVEs (CVE-2026-81963, CVE-2026-85880)
Microsoft's September 2026 Patch Tuesday fixes a record 964 CVEs, including two zero-days actively exploited in the wild.
Microsoft patched a record 964 CVEs in its September 2026 Patch Tuesday release, with 101 rated critical and 824 rated important, making it the largest Patch Tuesday to date. The release includes fixes for two zero-days that were exploited in the wild, with CVE-2026-81963 and CVE-2026-85880 highlighted in the release. Affected products span Windows core components, Office, Exchange, .NET, Visual Studio, Active Directory services (including AD CS and AD FS) and numerous Azure services. Tenable notes the release surpasses July's as the biggest ever.
Operation RapidRust: APT36 Deploys RUSTYSHADE, RUSTYMOVE, PSNATCH, and BASHNATCH
Zscaler details Operation RapidRust: APT36 deploys four new tools including RUSTYSHADE, a Rust backdoor using private GitHub repos for encrypted C2.
Zscaler ThreatLabz documents Operation RapidRust, a campaign by Pakistan-aligned APT36 deploying four new tools: RUSTYSHADE, a 64-bit Rust Windows backdoor that uses attacker-controlled private GitHub repositories with a hardcoded PAT and AES-256-GCM-encrypted messages for C2; RUSTYMOVE; PSNATCH, a PowerShell file stealer that scans Office documents, archives, media, and databases modified in the last 120 days and exfiltrates up to 5 GB per run to per-machine GitHub repositories; and BASHNATCH. The backdoor was dropped via PowerShell from attacker-controlled Backblaze B2 storage and supports screenshots, webcam capture, file listing, downloads, and shell command execution.
Microsoft Releases Emergency Windows 11 Update Following Patch Tuesday Bugs
Microsoft issued emergency Windows 11 update KB5129195 to fix Patch Tuesday regressions and fully close the CVE-2026-62721 privilege escalation flaw.
Microsoft shipped out-of-band cumulative update KB5129195 for Windows 11 24H2 and 25H2 (builds 26100.9457 and 26200.9457) after the September 8 Patch Tuesday rollup, which addressed over 960 CVEs including two actively exploited flaws, broke Remote Desktop Services, Hyper-V Plan9 folder sharing, and USB audio. The emergency release also strengthens the incomplete fix for CVE-2026-62721, an elevation-of-privilege flaw in the Windows User-Mode Power Service that could let a local attacker gain SYSTEM privileges. Companion patches cover Windows 11 26H1, Windows 10, and Windows Server. Some USB Audio Class 1.0 and AMD Radeon graphics issues remain unresolved.
Microsoft Patch Tuesday, September 2026 Security Update Review
Microsoft's September 2026 Patch Tuesday fixes 974 vulnerabilities, including 113 critical and two actively exploited Windows privilege escalation flaws.
Microsoft's September 2026 Patch Tuesday fixes 974 vulnerabilities, its largest release ever, including 113 critical and 860 important, covering Windows HTTP.sys, Hyper-V, Entra ID, Exchange Server, Office, DNS, and more. Two zero-days are confirmed exploited in the wild: CVE-2026-81963 (Windows Update Stack EoP) and CVE-2026-85880 (ALPC heap overflow), both letting authenticated attackers gain SYSTEM privileges. Notable criticals include an Entra ID authentication bypass (CVE-2026-62916) and multiple Windows DNS Server and Office remote code execution flaws.
Microsoft September 2026 Patch Tuesday Fixes 973 Vulnerabilities and 2 Exploited Zero-Days
Microsoft's September 2026 Patch Tuesday fixes 973 vulnerabilities, including two zero-days already exploited in the wild.
Microsoft's September 2026 Patch Tuesday addresses 973 vulnerabilities across Windows, Office, and Azure components, including two zero-days already exploited in the wild. CVE-2026-81963, an elevation of privilege flaw in the Windows Update Stack, is flagged as an exploited zero-day. The release includes numerous remote code execution and information disclosure fixes for Microsoft Excel and Word, plus patches for the Windows kernel, ALPC, Print Spooler, ReFS, Entra ID, and Azure CLI.
Microsoft Patch Tuesday for September 2026 — Snort rules and prominent vulnerabilities
Microsoft's September 2026 Patch Tuesday fixes 973 vulnerabilities, including 113 critical, with two Windows privilege-escalation bugs (CVE-2026-81963, CVE-2026-85880) exploited in the wild.
Microsoft's September 2026 security update addresses 973 vulnerabilities across its product lineup, 113 rated critical, of which 82 are remote code execution flaws. Two vulnerabilities are confirmed exploited in the wild: CVE-2026-81963, an elevation-of-privilege flaw in the Windows Update Stack (CVSS 7.8), and CVE-2026-85880, a heap-based buffer overflow in Windows Advanced Local Procedure Call (CVSS 7.8). Microsoft flags several bugs as more likely to be exploited, including a 9.8 RCE in Windows DNS Server (CVE-2026-69730), an 8.8 RCE in Windows Kerberos (CVE-2026-69676), and a 9.0 EoP in Spring Cloud Azure (CVE-2026-69854). Cisco Talos published accompanying Snort rules to detect exploitation attempts against the prominent flaws.
ThreatsDay: CEO Phishing Kits, 5K Dropbox Account Hacks, OAuth Traps + 17 More Stories
Microsoft warns of Teams IT-impersonation intrusions deploying Node.js implants; Spring Ring vishing hit 150+ employees across 10 companies; The Gentlemen ransomware claims 683 victims.
Microsoft warned of a human-operated campaign abusing Teams external collaboration to impersonate IT help desk staff, deploy malicious MSI packages staging Node.js runtimes and obfuscated JavaScript implants, then pivot to domain controllers over WinRM. Unit 42 documented the Spring Ring vishing operation targeting over 150 employees across at least 10 companies using 26 attacker identities, including an NTLM relay variant against domain controllers. Sophos reported The Gentlemen ransomware (Gold Sherwood) reached 683 total victims by end of July 2026, adding 169 in July, with a playbook using BYOVD-based EDR killers and backup tampering. Group-IB found the Outsider phishing-as-a-service platform created 700+ new phishing pages within a month despite law enforcement takedowns.
Malicious .git Configs Can Make Claude, Codex, Cursor, and Other AI Agents Run Attacker Code
Malicious .git core.fsmonitor configs let attacker code run in AI coding agents like Claude Code and Codex; four of eight flaws remain unpatched.
Manifold Security disclosed eight flaws across seven command-line AI coding agents where a repository's Git core.fsmonitor configuration causes agent-spawned commands to execute attacker code outside the sandbox and without approval prompts. Fixes shipped for goose (CVE-2026-72718, CVSS 4.0 score 7.0), Claude Code on one path, and Cursor, while Hermes Agent, Qwen Code, Grok Build, and a second Claude Code path were still unpatched as of September 1. OpenAI issued three CVEs for the same class in Codex, including CVE-2026-19592, and prior related bugs include CVE-2021-43891 in Visual Studio Code and CVE-2022-24346 in JetBrains IDEs. Exploitation requires the repository to arrive with its .git directory intact, such as via archives, shared drives, or USB sticks rather than an ordinary clone.
Global sinkhole operation ends Sality botnet’s 23-year run
Law enforcement, CrowdStrike, and Shadowserver sinkholed the 23-year-old Sality P2P botnet, cutting 15,000+ infected machines from its operator.
Sality, active since 2003 as a file-infecting virus with two P2P networks (versions 3 and 4), distributed credential thieves, spam, proxies, and DDoS payloads, and most recently delivered the EggJagger clipboard hijacker that swapped cryptocurrency wallet addresses for at least $150,000 in operator profit. A coordinated sinkhole operation replaced the botnet's super-peer list with defender-controlled sinkholes, and investigators in the US, Bulgaria, Hungary, and Romania seized payload domains. The Shadowserver Foundation is coordinating ISP and CERT notifications to infected device owners.
Threat Brief: Ongoing Russia and Ukraine Cyber Activity
Ukrainian government sites were defaced via OctoberCMS CVE-2021-32648 while Microsoft-attributed actor DEV-0586 deployed destructive WhisperGate malware.
Unit 42 tracks January 2022 attacks against Ukrainian government websites that were defaced or made inaccessible, which Ukraine attributed to Russia. Attackers exploited CVE-2021-32648, an account takeover flaw in OctoberCMS prior to 1.0.472, by submitting a boolean true as the password reset code to bypass validation. Separately, WhisperGate malware, attributed by Microsoft to DEV-0586, disabled Windows Defender and corrupted files across multiple Ukrainian organizations, using a ransomware-appearing first stage and an HTTPS-beaconing second stage with LOLBINs and anti-analysis techniques.