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.
Risky Bulletin: Slovakia finds Russian backdoor in traffic speed cameras
Slovakia's NBU found an SMS-triggered backdoor in Russian-made NERO R-ONE traffic cameras, pausing a 279-unit deployment.
Slovakia's national security service NBU issued an alert against NERO R-ONE high-speed traffic cameras after finding a backdoor that grants shell and network access via SMS from hardcoded Russian phone numbers. The cameras are a rebranded version of the Russian CORDON PRO.M model by St. Petersburg firm Semicon, purchased via a Cyprus shell company under a €30 million EU-funded project. The report also found SecureBoot disabled, vulnerable web management, and unauthenticated live streams; the Interior Ministry paused deployment of 279 cameras pending independent assessment.
The Smishing Deluge: China-Based Campaign Flooding Global Text Messages
Unit 42 attributes a global smishing campaign with 194,000+ phishing domains impersonating tolls, banks, and couriers to the Smishing Triad.
Palo Alto Unit 42 attributes ongoing smishing texts about toll violations and package misdelivery to the Smishing Triad, targeting U.S. residents since April 2024. Researchers identified 194,345 FQDNs across 136,933 root domains registered since January 2024, mostly via Hong Kong registrar Dominet (HK) Limited with Chinese nameservers and hosting concentrated on U.S. cloud services. The decentralized campaign impersonates banking, cryptocurrency, e-commerce, healthcare, law enforcement, and social media services, and its scale points to a large phishing-as-a-service operation. Phishing pages harvest national ID numbers such as Social Security numbers, home addresses, payment details, and login credentials.
Attackers are weaponizing the gap between Chromium fixes and Chrome patches
Espionage actors use the BlueMoon exploit kit to chain Chrome V8 and Windows kernel zero-days via spear phishing, gaining full admin on unpatched endpoints.
Proofpoint, working with Google Threat Intelligence Group, Microsoft Threat Intelligence Center and Volexity, reports that the BlueMoon exploit kit chains V8 type confusion CVE-2026-85046, V8 sandbox escape CVE-2026-87491 and Windows kernel LPE CVE-2026-85880, all rated high severity. The V8 flaws were fixed in upstream Chromium source but had not yet reached Chrome stable releases, creating a patch gap that attackers reverse-engineered and weaponized. A China-aligned state-sponsored actor used the kit from August 28 against a small number of US NGOs, mining and commodity trading firms via rapport-building spear phishing, and within days several mostly China-linked espionage clusters adopted BlueMoon. The chain yields full Windows admin privileges from a single phishing click; defenders should patch Chrome and Windows, apply Proofpoint detections and hunt for leftover artifacts.
Iran-Linked Hackers Use Fake LinkedIn Job Offers to Deploy NodeRabbit and PollCat RATs
Iran-linked Mirage Kitten targets software engineers with fake LinkedIn recruiter coding tests deploying new NodeRabbit and PollCat RATs.
Kaspersky researchers link the campaign to Mirage Kitten (also tracked as UNC1549, Smoke Sandstorm, Nimbus Manticore), with victims in aviation, aerospace and fintech in Egypt, Ethiopia and Afghanistan. Trojanized npm dependencies (colorized_terminal, pretty-log) bundled in coding-challenge archives launch the Node.js implants across Windows, Linux and macOS. NodeRabbit uses AES-256-GCM-encrypted C2 via Azure, and its third variant persists through a fake GitHub Copilot Helper VS Code extension plus Git post-merge/post-checkout hooks. PollCat is an obfuscated JavaScript RAT that registers with C2 before OTP authentication and inventories tools from 24 security vendors.
Persistent Attempts at Cyberespionage Against Southeast Asian Government Target Have Links to Alloy Taurus
Alloy Taurus (GALLIUM) compromised Southeast Asian government networks from 2022 to 2023 using Exchange web shells and undocumented .NET backdoors Reshell and Zapoa.
Unit 42 tracked persistent multiwave intrusions at a Southeast Asian government starting in early 2022 and continuing through 2023, attributing the activity with moderate confidence to Alloy Taurus (aka GALLIUM), a Chinese state-aligned espionage group. Attackers exploited Exchange Server vulnerabilities to deploy web shells including China Chopper, then ran reconnaissance with Fscan and WebScan, created administrative accounts, and installed undocumented .NET backdoors named Reshell and Zapoa. They established resilience by installing SoftEther VPN, brute-forced Active Directory credentials with Kerbrute, and dumped credential stores with GoDumpLsass and LsassUnhooker. The campaign reflects long-term espionage tradecraft to maintain a foothold.
Threat Brief: 3CXDesktopApp Supply Chain Attack (Updated)
Trojanized 3CXDesktopApp installers for Windows and macOS loaded RC4-encrypted shellcode delivering a backdoor to hundreds of thousands of 3CX users.
Threat actors compromised the 3CXDesktopApp build process, adding malicious libraries (ffmpeg.dll, d3dcompiler_47.dll) to installers downloaded from the developer's website. The Windows MSI loader decrypts embedded shellcode with RC4, sleeps for a random 1-4 weeks, then beacons to C2 hidden in icon files on GitHub. Unit 42 fingerprinted 247,277 IPs across 199 countries using 3CX applications and blocked shellcode execution at 127 Cortex XDR customers between March 9-30, 2023.
Microsoft September 2026 Patch Tuesday fixes 966 flaws, 2 zero-days
Microsoft's September 2026 Patch Tuesday fixes a record 966 flaws, including two Windows zero-days actively exploited to gain SYSTEM privileges.
Microsoft's September 2026 Patch Tuesday addresses a record 966 vulnerabilities, including 105 rated Critical, 81 of them remote code execution bugs. Two zero-days were actively exploited: a Windows Update Stack link-following flaw and a Windows ALPC heap-based buffer overflow, both allowing local elevation to SYSTEM privileges. The ALPC flaw was reported by Volexity and Proofpoint researchers, while the Update Stack flaw was credited to Romain Deperne and the Microsoft Threat Intelligence Centre. Microsoft shared no details on how the flaws were exploited in attacks.
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.
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’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.
September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)
Microsoft's September 2026 Patch Tuesday fixes a record 973 vulnerabilities, including 113 critical and two Windows privilege-escalation flaws already exploited in the wild.
Microsoft patched 973 vulnerabilities this month, its largest Patch Tuesday ever and far above the previous record of 664 set in July 2026, with 113 rated critical. Two Important elevation-of-privilege flaws (CVSS 7.8) are confirmed exploited in the wild: CVE-2026-81963 in the Windows Update Stack (improper link resolution, affects Windows 11 and Server 2025) and CVE-2026-85880 in Windows ALPC (heap-based buffer overflow allowing sandbox escape to SYSTEM, affects Windows 10 and Server 2012-2022). Critical unauthenticated RCEs (CVSS 9.8) were also fixed in Skype for Business Server (CVE-2026-66302), Windows Message Queuing (CVE-2026-69579), and Windows RRAS (CVE-2026-69590). SANS urges prioritizing the two exploited EoP fixes, then patching exposed MSMQ, RRAS, and Skype for Business deployments.
Suspected China-Nexus Actor Exploits VMware vCenter Flaw, Deploys Babuk
QUIRSO attributes exploitation of VMware vCenter CVE-2026-59310 to a suspected China-nexus actor that hit 361 IPs in 47 countries, deploying backdoors and Babuk.
German incident response firm QUIRSOS assessed with moderate confidence that a suspected China-nexus actor, likely operating in UTC+08:00 hours, exploited VMware vCenter flaw CVE-2026-59310 (CVSS 9.8 directory traversal) beginning five days after Broadcom's July 29 patch. The campaign compromised 361 unique victim IPs across 47 countries, most in Germany, the US, Turkey, Iran, and France. The actor abused cron jobs, a XOR-obfuscated 'linuxFile' WebSocket backdoor with systemd/cron persistence, a JSP web shell, SSH authorized-keys manipulation, and a reverse SSH tool, with one Babuk deployment reported. A separate vCenter 'vcenter_admin' account creation consistent with CVE-2026-59309 exploitation was also observed from August 1.
Patch Tuesday - September 2026
Microsoft's September 2026 Patch Tuesday fixes 999 CVEs, a record, with two zero-day privilege escalation flaws already exploited in the wild.
Microsoft published 974 own-product vulnerabilities plus 25 non-Microsoft CVEs, totaling 999 — the most CVEs Microsoft has ever released in a single day. Two flaws are exploited in the wild: CVE-2026-85880, an out-of-bounds write in Windows ALPC granting SYSTEM privileges, and CVE-2026-81963, an improper link resolution flaw in the Windows Update Stack also leading to SYSTEM. Chrome's V8 zero-day CVE-2026-85046 was patched in Edge on September 2, but Microsoft had not published a corresponding advisory, leaving uncertainty about other Chromium fixes in Edge. October 14 lifecycle changes end servicing for Windows 11 24H2 Home/Pro, Office 2021, and Exchange Server 2016/2019.
August 2026 CVE Landscape
Insikt Group catalogs 73 high-impact August 2026 CVEs (43 Very Critical), including PaperCut, Zimbra, and Metabase flaws actively exploited or weaponized.
Recorded Future's Insikt Group identified 73 high-impact vulnerabilities in August 2026, 43 rated Very Critical, spanning 45 vendors with Microsoft accounting for roughly 11%. 31 vulnerabilities surfaced via CISA's KEV catalog, with others validated via open sources, vendor telemetry, and honeypot data. New Nuclei detection templates were released for CVE-2025-62593 (Ray), CVE-2026-72898 (Metabase), and CVE-2026-9198 (IBM Langflow). The report also highlights two AI-assisted operations: UAT-10147 exploited Zimbra, AjaxPro, Nacos, and Telerik servers before using DeepAudit and PentestGPT post-compromise, while a separate Chinese-speaking actor weaponized Hermes Agent and DeepSeek in a failed attempt.
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.
The September 2026 Security Update Review
ZDI's September 2026 Microsoft update review lists two already-exploited Windows EoP zero-days and dozens of critical RCEs across Office, SQL Server, and Windows services.
The review catalogs Microsoft's September 2026 fixes, marking CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack) as already exploited elevation-of-privilege issues. It also lists critical RCE flaws in Office, Word, Excel, PowerPoint, Outlook, SQL Server, Windows DNS, DHCP and Failover Cluster, plus graphics component RCEs. Azure-side fixes include Entra ID, Copilot Studio, Azure AI Language and Azure AD B2C elevation-of-privilege flaws.