ZeroHour

Search: “microsoft-windows”

24 stories

Smart search ranks by meaning as well as keywords (one row per story, last 45 days).

Microsoft named a Leader in the Frost Radar™: Cloud Workload Protection Platforms, 2026

Microsoft was named a leader in the 2026 Frost Radar for Cloud Workload Protection Platforms, cited for Defender for Cloud runtime security.

The 2026 Frost Radar for Cloud Workload Protection Platforms placed Microsoft in its leadership tier, calling the company a visionary leader. Microsoft attributes the recognition to unified runtime security delivered through Microsoft Defender for Cloud. The post is vendor marketing with no incident, vulnerability, or technical detail.

Microsoft Security Blog · 27d agoIndustry3

Microsoft Defender's Own Driver Can Be Weaponized to Delete Security Software at Boot

Check Point revealed BTR Reforged, a technique weaponizing Microsoft Defender's built-in BTR.sys driver to delete security software at boot without exploiting any vulnerability.

Check Point Research disclosed BTR Reforged, a technique that abuses BTR.sys, a legitimately signed Windows Defender boot-time remediation driver, to perform arbitrary kernel-level file and registry operations on Windows 7 through Windows 11 25H2 without exploiting a software flaw. The BTR_CLI proof-of-concept tool, presented at Black Hat USA 2026 and DEF CON 34, installs the driver via direct registry writes and executes deletions during the boot-time 'golden window' before Defender's user-mode services start, demonstrated by deleting the full Defender stack on a patched Windows 11 machine. Exploitation requires SeLoadDriverPrivilege; Microsoft confirmed it does not meet criteria for immediate servicing and no patch is planned. No evidence of real-world abuse was found, and related indicators of compromise via Sysmon events were published.

The Hacker News · 26d agoToolsCVE-2021-240921

Microsoft Patch Tuesday Update September 2026 – 974 Vulnerabilities Fixed, Including 2 Zero-Days

Microsoft's September 2026 Patch Tuesday fixes 974 vulnerabilities across Windows and Office, including two actively exploited Windows privilege-escalation zero-days.

Microsoft's September 2026 Patch Tuesday addresses 974 vulnerabilities spanning Windows, Office, SQL Server, SharePoint, Exchange, Azure, and developer tools. Two Windows zero-days are confirmed exploited in attacks: CVE-2026-85880, a Windows ALPC elevation-of-privilege flaw, and CVE-2026-81963, a Windows Update Stack privilege-escalation flaw involving link following. The release also includes Critical fixes for Windows Secure Kernel Mode, VBS Enclave, Excel, and Word.

Microsoft Plugs Nearly 400 Security Holes

Microsoft's August 2026 Patch Tuesday fixes 398 vulnerabilities, including one flaw already being actively exploited and two publicly disclosed before the update.

Microsoft released August 2026 Patch Tuesday updates fixing at least 398 vulnerabilities in Windows and supported software. One of the flaws is already being actively exploited, and two others were publicly detailed ahead of the patch release. The update is one of the larger monthly releases in recent memory.

Krebs on Security · Aug 11, 2026Vulnerability in the wild2

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.

BleepingComputer · 7d agoAdvisory in the wildCVE-2026-69805CVE-2026-58649CVE-2026-69806+27 CVEs1

Windows 11 cumulative updates KB5124008 & KB5122880 released

Microsoft shipped mandatory September 2026 Patch Tuesday cumulative updates KB5124008 and KB5122880 for Windows 11, fixing vulnerabilities and adding features.

Microsoft released Windows 11 KB5124008 (versions 25H2/24H2) and KB5122880 (23H2) cumulative updates containing the September 2026 Patch Tuesday security patches, described as covering 1,000 vulnerabilities discovered in previous months. The updates are mandatory and add features including movable and resizable taskbars, Start menu customization, a Windows Search option to hide Bing and Store web suggestions, and Administrator Protection, a just-in-time admin privilege feature that is off by default and configurable via Intune OMA-URI or Group Policy.

BleepingComputer · 7d agoAdvisory

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.

Fake Software Installers Disable Windows Update and Weaken Microsoft Defender

Fake software-download sites distribute installers that disable Windows Update and weaken Defender, attributed to China-linked cluster Silver Fox.

Microsoft says an active campaign uses counterfeit vendor websites on .com.cn and .hl.cn infrastructure with Chinese-language lures to deliver server-side generated installers that establish scheduled-task persistence, add Defender exclusions, delete shadow copies, and stop services including wuauserv, UsoSvc, uhssvc and WaaSMedicSvc. Victims span healthcare, manufacturing, gaming, technology, logistics, government and education, primarily China-based operations of multinationals and Chinese-speaking users. Microsoft assesses with moderate confidence the activity matches the Silver Fox (Yinhu) cluster, historically tied to Gh0st RAT and ValleyRAT, with C2 over non-standard ports like 5090 and 7088-7090 via domains iualef[.]net and oijfwe[.]net. Kaspersky separately detailed a QN Wallpaper DLL-sideloading chain delivering ValleyRAT.

The Hacker News · 13d agoMalware in the wild

Nightmare-Eclipse Strikes Again with 'ShieldCrash' Windows Exploit

A researcher known as Nightmare-Eclipse published another zero-day exploit, dubbed ShieldCrash, targeting Windows Defender.

Dark Reading reports that the disgruntled researcher tracked as Nightmare-Eclipse continued a vendetta against Microsoft by publishing a new zero-day exploit named ShieldCrash for Windows Defender. The brief report does not detail affected versions, exploitation prerequisites, or whether exploitation has been observed.

Dark Reading · 6d agoExploit / PoC1

Counterfeit installers to system compromise: Tracking a deceptive software download campaign

Microsoft tracks a counterfeit software-installer campaign compromising multinationals' China operations, moderately linked to the Silver Fox (Yinhu) actor.

Microsoft Defender Experts is tracking an active campaign using spoofed software download sites for brands such as Razer, Kaspersky, Microsoft Edge, Calibre, and Baidu Netdisk on .com.cn and .hl.cn domains, delivering installer archives whose hashes change per download, indicating server-side payload generation. The implants establish persistence, weaken security protections, and communicate with attacker-controlled infrastructure, with confirmed compromises across healthcare, manufacturing, gaming, technology, logistics, government, and education. Microsoft assesses with moderate confidence that the activity matches the publicly reported Silver Fox (Yinhu) fake software campaign; it has not attributed it to a nation-state actor.

Microsoft Security Blog · 14d agoThreat actor in the wild1

Counterfeit installers turn routine software downloads into enterprise breaches

Microsoft warns of a multi-sector campaign using counterfeit download sites for Edge, Kaspersky and Razer to deliver trojanized installers with persistent implants.

Microsoft Defender Experts tracked a campaign breaching organizations in healthcare, manufacturing, gaming, technology, logistics, government, and education via spoofed vendor download pages, often using .com.cn and .hl.cn domains. Installers keep the same filename while their hash changes on every download, indicating server-side payload generation that defeats file-based detection. The chain abuses msiexec.exe and scheduled tasks for persistence, adds Defender exclusions, deletes shadow copies, and disables Windows Update, with some hands-on-keyboard activity. The activity is consistent with the publicly reported Silver Fox (Yinhu) campaign, though Microsoft has not attributed it to a nation-state actor.

CSO Online · 13d agoThreat actor in the wild1

Microsoft Plugs Nearly 1,000 Security Holes

Microsoft's September Patch Tuesday fixes a record 974 flaws, including two actively exploited Windows zero-days and critical DNS and Windows Shell bugs.

Microsoft released fixes for 974 vulnerabilities, its largest-ever monthly patch batch, bringing the 2026 total above 2,600. Two zero-day privilege elevation flaws, CVE-2026-81963 and CVE-2026-85880, are being actively exploited. Critical bugs include CVE-2026-69730, an unauthenticated DNS weakness in Windows Server 2012 onward and Windows 10 deemed likely to be exploited, and CVE-2026-69829, a CVSS 9.8 Windows Shell remote code execution flaw requiring no privileges or user interaction. Microsoft and other vendors credit AI-assisted discovery for the growing patch volumes.

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.

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.

New Windows Defender ShieldCrash 0-Day Bypasses Microsoft Patch to Read Files as SYSTEM

Researcher's ShieldCrash PoC claims Microsoft Defender still allows arbitrary file reads as SYSTEM on patched Windows, bypassing the CVE-2026-69414 fix.

Researcher MSNightmare released the ShieldCrash proof of concept showing Microsoft Defender can allegedly be made to read arbitrary files with SYSTEM privileges on fully patched Windows systems, bypassing the September 2026 fix for ShieldBreak (CVE-2026-69414). Microsoft has not confirmed the bypass, and the new flaw has no CVE assignment yet. The PoC repository contains C++ project files, a Warden.dll library, and an EICAR test archive, suggesting interaction with Defender's malware-detection and file-handling workflow. Reading files as SYSTEM could expose configuration files, credentials, private keys, and other users' data, though it does not enable code execution.

Windows memory integrity switches on automatically for eligible devices in October 2026

Microsoft's Windows quality updates will automatically enable memory integrity and Virtualization-based Security on eligible devices starting October 2026.

Beginning in October 2026, Windows quality updates will automatically enable memory integrity on eligible devices and turn on Virtualization-based Security where it is not already running. Memory integrity restricts kernel-mode execution to trusted, signed code and drivers, blocking kernel compromise and rootkits. Microsoft said existing administrator decisions remain in effect, and readiness checks weigh hardware capability, compatibility, and performance. Memory integrity also underpins hotpatch updates that install without a reboot, so unprotected devices are excluded from that servicing model.

Help Net Security · 13d agoAdvisory

Microsoft Patches Record 974 Flaws, Including Two Exploited Windows Zero-Days

Microsoft's September Patch Tuesday fixed a record 974 flaws, including two Windows privilege-escalation zero-days actively exploited and added to CISA's KEV catalog.

Microsoft's September 2026 Patch Tuesday addressed a record 974 vulnerabilities (999 including 25 non-Microsoft CVEs), with over 110 rated critical; 723 affect Windows and 111 affect Office. Two Windows privilege-escalation zero-days are actively exploited: CVE-2026-85880, an ALPC heap-based buffer overflow, and CVE-2026-81963, an improper link resolution flaw in the Windows Update Stack, both allowing attackers to gain SYSTEM privileges. CISA added both flaws to its KEV catalog, giving federal civilian agencies until September 22, 2026 to apply fixes. Volexity, Proofpoint, MSTIC, and independent researchers were credited with the reports; notable additional fixes include network-reachable RCEs in Exchange, SharePoint, SQL Server, Remote Desktop Services, DNS, and DHCP.

The Hacker News · 7d agoExploit / PoC in the wildCVE-2026-85880CVE-2026-81963CVE-2026-55007+9 CVEs

Microsoft security advisory – August 2026 monthly rollup (AV26-804) – Update 2

Canada's Cyber Centre updated advisory AV26-804 relaying Microsoft's August 2026 monthly rollup of vulnerabilities across .NET and Azure products.

The Canadian Centre for Cyber Security advisory AV26-804, updated August 27, 2026, relays Microsoft's August 2026 monthly security rollup originally issued August 11. Affected products include .NET 8.0, 9.0, and 10.0 on Linux, macOS, and Windows, plus many Azure services. Listed Azure components include Azure Kubernetes Service, Azure SQL Database, Azure Service Bus, Azure Active Directory, Azure Logic Apps, and Azure Monitor Agent.

Canadian Centre for Cyber Security · 19d agoAdvisory1

Microsoft patches a record 972 vulnerabilities, 112 of them critical

Microsoft's September Patch Tuesday fixes a record 972 vulnerabilities, 112 rated critical, including two zero-days in Windows components.

Microsoft's September 2026 release patched roughly 972 vulnerabilities (997 including ported Chromium fixes for Edge), a record, with 112 rated critical. Notable flaws include two zero-days: CVE-2026-81963 in the Windows update service and CVE-2026-85880 in the Windows Advanced Local Procedure, with no public information on exploitation breadth. Microsoft has fixed 2,760 vulnerabilities in 2026, more than double last year's total, which ZDI's Dustin Childs attributes to AI-assisted discovery becoming the 'new normal'.

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.

BleepingComputer · 7d agoAdvisory in the wild

Microsoft releases emergency Windows updates to fix RDS failures

Microsoft released emergency out-of-band Windows updates fixing Remote Desktop Services failures and Hyper-V issues caused by September 2026 security patches.

Microsoft issued out-of-band updates on September 14, 2026 to fix Remote Desktop Services instability introduced by the September security updates, which caused RDP connection and sign-in failures and unresponsive servers. Updates include KB5129194 (Windows 11 26H1), KB5129195 (Windows 11 24H2/25H2), KB5129236 (Windows 10), KB5129235 (Windows Server 2025), and KB5129237 (Windows Server 2022). The Windows 11 updates also fix a Hyper-V Plan9 shared folder issue and some USB Audio Class 1.0 multichannel problems, though remaining USB audio issues await a fix. Admins had previously used Group Policy mitigations or uninstalled the security updates, which removed security protections.

BleepingComputerupdated · 1d agofirst · 1d agoAdvisory 3 sources1

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.

Cyber Security News · 8h agoVulnerability in the wildCVE-2026-62721

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.

GBHackers · 7d agoAdvisory in the wildCVE-2026-85880CVE-2026-85877CVE-2026-85875+27 CVEs1