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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.

Tenable Blog · 8d agoVulnerability in the wildCVE-2026-81963CVE-2026-858801

CVE-2026-73749: HPE ArubaOS-CX RCE

HPE patched CVE-2026-73749, a critical unauthenticated remote code execution flaw in ArubaOS-CX network switch software; affected devices need prompt updates.

HPE released patches for CVE-2026-73749, a critical unauthenticated remote code execution vulnerability in HPE Aruba Networking AOS-CX switch operating system. Published details are limited, but the flaw allows unauthenticated attackers to execute code on affected AOS-CX devices. Administrators running ArubaOS-CX should prioritize applying HPE's update.

SOCRadar · 12d agoVulnerabilityCVE-2026-73749

SAP Patches Critical Extended Passport Processing Vulnerability

SAP patches CVSS 10.0 flaw CVE-2026-44756 (OVERPASS) enabling unauthenticated RCE in S/4HANA and NetWeaver, plus three other criticals; no in-the-wild exploitation reported.

CVE-2026-44756 is a CVSS 10.0 memory corruption flaw in Extended Passport (EPP) deserialization, triggered when a user session opens across web, SAP GUI, and RFC vectors. Exploitation yields command execution as the SAP OS account, database credential and password hash recovery, session reading, and data or binary modification; affected products include S/4HANA, ERP/ECC, NetWeaver, Web Dispatcher, and BW/4HANA. Three other criticals were patched: CVE-2026-58240 (S4GET, missing authentication affecting all S/4HANA 2025 and earlier releases), CVE-2026-76969 (CAP credential disclosure), and CVE-2026-66768 (NetWeaver access control). Onapsis and SAP report no indicators of in-the-wild exploitation.

CVE-2026-34908, CVE-2026-34909, CVE-2026-34910: Ubiquiti UniFi OS ...

Ubiquiti UniFi OS flaws CVE-2026-34908, CVE-2026-34909, and CVE-2026-34910 were added to CISA's KEV, chaining auth bypass into command injection.

Ubiquiti UniFi OS vulnerabilities CVE-2026-34908, CVE-2026-34909, and CVE-2026-34910 were added to CISA's KEV catalog. CVE-2026-34908 (CVSS 10.0, CWE-284) is an unauthenticated improper access control flaw allowing unauthorized system changes, described as the initial entry point. It enables attackers to then leverage chained path traversal and command injection flaws for deeper compromise.

SAP Commerce Cloud CVE-2026-58231 Targeted in Exploitation Attempts Days After Patch

A maximum-severity (CVSS 10.0) unauthenticated RCE flaw in SAP Commerce Cloud, CVE-2026-58231, is under active exploitation days after patching.

CVE-2026-58231, rated 10.0 on CVSS, stems from insufficient authorization checks and input validation in SAP Commerce Cloud, enabling unauthenticated arbitrary code execution. Defused Cyber's honeypots detected exploitation attempts three days after the patch, and KEVIntel independently confirmed two attempts on August 14 from a US IP address. Onapsis urges customers to patch and rebuild, with an IP Filter Set offered as a temporary workaround. No actor attribution yet, though prior SAP NetWeaver flaw CVE-2025-31324 was exploited by China-nexus and criminal groups.

The Hacker News · Aug 17, 2026Exploit / PoC in the wildCVE-2026-58231CVE-2025-31324

Microsoft’s Biggest Patch Tuesday: 974 CVEs, 2 Zero-Days and 20 Wormable Bugs

Microsoft's record September 2026 Patch Tuesday fixes 974 CVEs, including two exploited Windows privilege-escalation zero-days and 20 wormable bugs.

Microsoft's September 2026 Patch Tuesday fixes a record 974 CVEs, including two actively exploited zero-days: CVE-2026-85880, an ALPC heap buffer overflow, and CVE-2026-81963 in the Windows Update Stack, both CVSS 7.8 local privilege escalations. It also addresses an unauthenticated Exchange RCE (CVE-2026-55007) triggered by Visio attachment content indexing under memory pressure, an RDP use-after-free (CVE-2026-69525, CVSS 9.8), and 20 wormable flaws in DNS, DHCP, SMB, Active Directory, and other components. ZDI attributed the rising volume partly to AI-assisted vulnerability discovery, noting no corresponding spike in active exploits yet.

Security Affairs · 7d agoVulnerability in the wildCVE-2026-85880CVE-2026-81963CVE-2026-55007+3 CVEs2

CVE-2026-34908: Ubiquiti Networks UniFi OS Server access control ...

CVE-2026-34908, a CVSS 10.0 access-control bypass in Ubiquiti UniFi OS, was added to CISA's KEV catalog amid reported active exploitation.

CISA added CVE-2026-34908 to the Known Exploited Vulnerabilities catalog on June 23, 2026, with remediation due June 26 under BOD 26-04 guidance. The CVSS 10.0 improper access control flaw (CWE-284) in Ubiquiti UniFi OS allows unauthorized system changes without authentication. Multiple news reports referenced by the page describe the max-severity UniFi flaws being exploited in attacks, and an official patch is available.

ISC has disclosed fourteen vulnerabilities in BIND 9 (CVE-2026-19033, CVE-2026-19662, CVE-2026-19666, CVE-2026-19667, CVE-2026-19668, CVE-2026-19941, CVE-2026-75029, CVE-2026-76163, CVE-2026-77119, CVE-2026-77692, CVE-2026-78301, CVE-2026-80274, CVE-2026-81563, CVE-2026-81736)

ISC discloses fourteen vulnerabilities in BIND 9 DNS software, including a use-after-free, with fixes now available.

On September 16, 2026, Internet Systems Consortium disclosed fourteen vulnerabilities affecting BIND 9, listing CVE-2026-19033, CVE-2026-19662, CVE-2026-19666 (use-after-free), CVE-2026-19667, CVE-2026-19668, CVE-2026-19941, CVE-2026-75029, CVE-2026-76163, CVE-2026-77119, CVE-2026-77692, CVE-2026-78301, CVE-2026-80274, CVE-2026-81563, and CVE-2026-81736. Details and fixes are published in the ISC knowledge base. No active exploitation is reported in the announcement.

Microsoft breaks Patch Tuesday record with 974-CVE deluge

Microsoft's record 974-CVE Patch Tuesday ships two exploited Windows zero-days, while Adobe's StyleSmuggler zero-day (CVE-2026-75650) gives unauthenticated RCE in Magento.

Microsoft's September Patch Tuesday addresses 974 CVEs, including two zero-days already under exploitation: CVE-2026-85880, a Windows ALPC privilege escalation leading to SYSTEM via sandbox escape, and CVE-2026-81963, a Windows Update Stack privilege escalation. Adobe patched 172 CVEs, including the max-severity StyleSmuggler zero-day CVE-2026-75650 in Magento and Adobe Commerce, which Sansec reports is being exploited since September 4 to inject PHP into templates and install a C2-connected backdoor. CISA added CVE-2026-85880, CVE-2026-81963, and CVE-2026-75650 to its Known Exploited Vulnerabilities Catalog with patch deadlines of September 22 and September 11. The piece also notes Google-patched Chrome V8 zero-day CVE-2026-85046 lacks a Microsoft advisory for Edge, and flags nine Exchange Server flaws including remote unauthenticated RCE CVE-2026-55007.

AL26-019 - Vulnerabilities impacting Citrix NetScaler ADC and NetScaler Gateway - CVE-2026-19490 and CVE-2026-19489

Canadian Cyber Centre alerts on Citrix NetScaler ADC/Gateway flaws CVE-2026-19490 (authentication bypass) and CVE-2026-19489 (buffer overflow), urging emergency patching.

The Canadian Centre for Cyber Security issued alert AL26-019 covering two Citrix NetScaler vulnerabilities disclosed in a vendor advisory on August 19, 2026. CVE-2026-19490 (CWE-288) allows a remote unauthenticated attacker to bypass authentication on appliances configured as a Gateway for SSL VPN, ICA Proxy, CVPN, RDP Proxy, or as an AAA virtual server. CVE-2026-19489 (CWE-120) is a classic buffer overflow that may cause memory overflow, unpredictable behavior, or denial-of-service conditions. Affected appliances are vulnerable when configured as a SAML IdP; fixed versions include 14.1-73.32, 13.1-63.21, and 13.1-37.277 for FIPS.

You’re Back In The Room (Citrix NetScaler Pre-Auth RCE CVE-2026-8452(?))

watchTowr Labs details a pre-authentication remote code execution flaw, tracked as CVE-2026-8452, in Citrix NetScaler appliances.

watchTowr Labs published technical analysis of a pre-authentication remote code execution vulnerability in Citrix NetScaler, tentatively assigned CVE-2026-8452. The CVE identifier is marked as provisional in the write-up. No confirmation of in-the-wild exploitation is provided in the available text.

watchTowr Labs · Aug 14, 2026Exploit / PoCCVE-2026-8452

CVE-2026-78318: Apache Syncope: Unauthenticated reflected XSS in Console and Enduser

Apache Syncope Console and Enduser UIs suffer unauthenticated reflected XSS via notification messages, affecting versions 4.0.4 through 4.1.2.

CVE-2026-78318 is a moderate-severity cross-site scripting flaw in Apache Syncope's syncope-client-idrepo-common-ui module. The notification message, optionally shown by the Console and Enduser UIs, is improperly neutralized, enabling unauthenticated reflected XSS. Affected versions are 4.0.4 through 4.0.7 and 4.1.0-M0 through 4.1.2; no exploitation is reported.

oss-security · 2d agoVulnerabilityCVE-2026-783181

SAP Patches CVSS 10.0 Kernel Flaw Enabling Unauthenticated Remote Code Execution

SAP patched CVE-2026-44756 (CVSS 10.0), an unauthenticated kernel memory corruption allowing OS command execution, plus three other critical flaws.

SAP's September security updates include CVE-2026-44756 (OVERPASS, CVSS 10.0), a missing boundary validation during deserialization of Extended Passport (EPP) data in the SAP kernel, enabling unauthenticated attackers to run arbitrary OS commands with SAP administrative privileges. Also patched: CVE-2026-58240 (S4GET, CVSS 9.8), a missing authentication check in SAP NetWeaver Message Server yielding RCE as <sid>adm; CVE-2026-76969 (9.4), credential disclosure in SAP Cloud Application Programming Model multi-tenant apps; and CVE-2026-66768 (9.0), improper access control in SAP NetWeaver SAP GUI for Java. Onapsis, which discovered the flaws, says none have been exploited to date and recommends prioritizing internet-facing SAP systems.

[0day-rubbish] OP5 Monitor 9.20 Command injection surviving the CVE-2025-34115 patch (OPT-IN fix ineffective) (8.8)

OP5 Monitor 9.20 remains vulnerable to CVSS 8.8 command injection because the CVE-2025-34115 fix is opt-in and ineffective.

0day Rubbish Research Team disclosed a command injection (CWE-78) in OP5 Monitor 9.20 that survives the existing CVE-2025-34115 patch, which is opt-in and described as ineffective. The issue scores CVSS 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). Administrators who previously applied the vendor fix may still be exposed.

Adobe Commerce max-severity bug comes under active attack

Attackers are actively exploiting CVE-2026-75650 (CVSS 10.0), an unauthenticated RCE zero-day in Adobe Commerce/Magento, deploying a Rust backdoor on e-commerce servers.

Sansec identified active exploitation of a CVSS 10.0 zero-day (CVE-2026-75650) in Adobe Commerce and Magento Open Source versions 2.4.4 through 2.4.9, dubbed StyleSmuggler. The attack abuses crafted style properties in Magento template processing to execute PHP while rendering a 'Payment Transaction Failed Reminder' email, then launches a Rust backdoor connecting to C2 at 99.84.67.186 disguised as NTP traffic. Exploitation began September 4, 2026; Adobe released emergency hotfix VULN-393411, but Sansec also observed a second attacker deploying a PHP web shell in the product-image cache.

CSO Online · 8d agoExploit / PoC in the wildCVE-2026-75650

2026-011: Critical Vulnerabilities in SAP Kernel and NetWeaver Message Server

SAP patched two critical flaws, OVERPASS (CVE-2026-44756, CVSS 10.0) and S4GET (CVE-2026-58240), allowing unauthenticated attackers to execute OS commands on SAP hosts.

On SAP's September 2026 Security Patch Day, SAP released Security Notes 3747649 and 3759472 fixing two critical unauthenticated remote vulnerabilities found by Onapsis. CVE-2026-44756 ('OVERPASS', CVSS 10.0) is a memory corruption flaw in Extended Passport (EPP) deserialisation in the SAP Kernel; CVE-2026-58240 ('S4GET', CVSS 9.8) is a missing authentication check in the NetWeaver Message Server that lets attackers register as trusted cluster nodes. Successful exploitation of either can yield OS command execution as the SAP service account, leading to full system and business data compromise, and CERT-EU urges immediate patching. No in-the-wild exploitation is reported.

September 2026 Patch Tuesday roundup: Plugs for two zero day holes among almost 1,000 fixes in Windows

Microsoft's September 2026 Patch Tuesday ships 964 fixes including two exploited Windows zero-days (CVE-2026-85880, CVE-2026-81963) and a wormable DNS RCE.

Microsoft's September 2026 Patch Tuesday includes 964 Microsoft vulnerabilities requiring customer action, a record attributed to AI-assisted bug discovery, plus 174 third-party/open-source and 23 Chromium/Edge CVEs. Two zero-days are exploited in the wild: CVE-2026-85880, a Windows ALPC heap overflow enabling AppContainer sandbox escape and privilege escalation, and CVE-2026-81963, a Windows Update Stack escalation to SYSTEM. CVE-2026-69730, an unauthenticated Windows DNS RCE, is not yet exploited but Microsoft expects exploitation, and roughly 20 bugs could be wormable. Separately, SAP issued a critical CVSS 10.0 fix for the EPP component used in S/4HANA and NetWeaver.

CSO Online · 7d agoVulnerability in the wildCVE-2026-85880CVE-2026-81963CVE-2026-69730+2 CVEs1

CVE-2026-19490: Critical Vulnerability Affecting Citrix NetScaler ADC and NetScaler Gateway

CVE-2026-19490 is a critical unauthenticated authentication bypass in Citrix NetScaler ADC and Gateway, remotely exploitable without user interaction.

An advisory published August 19, 2026 describes CVE-2026-19490, a critical authentication bypass affecting Citrix NetScaler ADC and NetScaler Gateway. The flaw carries a CVSS v4.0 base score of 9.3 and is remotely exploitable by unauthenticated attackers over the network without user interaction or elevated privileges. NetScaler ADC and Gateway are widely deployed enterprise products positioned at or near the network perimeter, providing load balancing, SSL/TLS offloading, and secure remote access. The text does not state whether exploitation has been observed in the wild.

Rapid7 Blog · 28d agoVulnerabilityCVE-2026-194901

Microsoft's August 2026 Patch Tuesday addresses 398 CVEs (CVE-2026-68820)

Tenable reports Microsoft's August 2026 Patch Tuesday addresses 398 CVEs including three zero-days, one exploited in the wild (CVE-2026-68820).

Microsoft patched 398 CVEs in its August 2026 Patch Tuesday release, with 42 rated critical, 355 important, and one moderate, and three zero-days among them. One zero-day is confirmed as exploited in the wild. The release covers components including .NET, .NET Framework, Active Directory Certificate Services (AD CS), Azure services, and Windows. Tenable's count omits two CVEs assigned by MITRE, CVE-2026-6726 and CVE-2026-6727.

Tenable Blog · Aug 11, 2026Vulnerability in the wildCVE-2026-68820CVE-2026-6726CVE-2026-67271

Broadcom Patches Critical VMware Workstation and Fusion VM

Broadcom patched critical VMware Workstation and Fusion VM-escape flaws CVE-2026-59346 (CVSS 9.3) and CVE-2026-59347 (CVSS 8.1); update to 26H1u1.

Advisory VMSA-2026-0007 fixes CVE-2026-59346 (CVSS 9.3), an integer overflow in the VMXNET3 virtual network adapter, and CVE-2026-59347 (CVSS 8.1), a stack-based buffer overflow in HGFS. A malicious actor with local administrative privileges inside a VM could execute code on the host in both cases. The flaws affect Workstation and Fusion 25H2 and 26H1 and are fixed in version 26H1u1 with no workarounds available. The bugs were reported independently by researchers working with Trend Micro Zero Day Initiative and by Tencent Xuanwu Lab.

U.S. CISA adds maximum-severity Oracle flaw to its Known Exploited Vulnerabilities catalog

CISA added actively exploited CVE-2026-21962, a CVSS 10.0 unauthenticated flaw in Oracle HTTP Server and WebLogic Proxy Plug-in, to KEV with an August 27 deadline.

CISA added CVE-2026-21962 (CVSS 10.0), an improper access control vulnerability in Oracle HTTP Server and the Oracle WebLogic Server Proxy Plug-in, to its Known Exploited Vulnerabilities catalog and ordered federal agencies to remediate by August 27, 2026. The unauthenticated flaw allows remote attackers with network access to create, delete, or modify critical data, potentially gain broad access, and cause a scope change to other systems; affected versions are 12.2.1.4.0, 14.1.1.0.0 and 14.1.2.0.0. CloudSEK honeypot data from January-February 2026 showed widespread exploitation of the flaw alongside older WebLogic RCEs including CVE-2020-14882/14883, CVE-2020-2551, and CVE-2017-10271.

Security Affairs · 22d agoExploit / PoC in the wildCVE-2026-21962CVE-2020-14882CVE-2020-14883+2 CVEs

OpenVPN security advisory (AV26-889)

Canada's Cyber Centre advisory AV26-889 flags CVE-2026-84732 in OpenVPN 2.6.22 and earlier and 2.7.6 and earlier, urging administrators to apply updates.

The Canadian Centre for Cyber Security issued advisory AV26-889 noting that OpenVPN versions up to and including 2.6.22 and 2.7.6 are affected by CVE-2026-84732. The flaw involves unbounded TLS timeouts and acknowledgements for non-outstanding packets in the reliability layer. Administrators are encouraged to review the linked OpenVPN guidance and apply updates as they become available. No exploitation is reported.

Cisco confirms CVE-2026-20079 Secure FMC flaw exploited in attacks

Cisco confirmed active exploitation of CVE-2026-20079, a CVSS 10.0 authentication bypass enabling unauthenticated root command execution in Secure FMC; CISA added it to KEV.

Cisco confirmed in August 2026 that CVE-2026-20079 (CVSS 10.0), an unauthenticated authentication bypass in Secure Firewall Management Center, is being actively exploited, allowing remote attackers to execute scripts and commands as root via crafted HTTP requests to the web interface. CISA added the flaw to its Known Exploited Vulnerabilities catalog, ordering federal civilian agencies to patch by September 12, 2026. Shared IOCs, identical hot fixes, and a July 23 log entry suggest CVE-2026-20079 was used alongside the separately exploited static-credential flaw CVE-2026-20316 in the same attacks. Cisco released patches and cloud fixes, warns hot fixes do not remediate already-compromised devices, and says there are no workarounds.

BleepingComputer · 7d agoExploit / PoC in the wildCVE-2026-20079CVE-2026-20316

Critical VMware Workstation and Fusion Flaw Lets VM Admins Execute Host Code

Broadcom patched two VMware Workstation and Fusion flaws, including critical integer overflow CVE-2026-59346 (CVSS 9.3), letting guest admins execute host code; no exploitation seen.

Broadcom released updates fixing CVE-2026-59346 (CVSS 9.3), an integer-overflow vulnerability allowing a malicious actor with local administrative privileges on a VM with a VMXNET3 adapter to execute code on the host, and CVE-2026-59347 (CVSS 8.1), a stack-based buffer overflow in HGFS allowing code execution as the host's VMX process. Both flaws affect VMware Workstation and Fusion 25H2 and 26H1, have no workarounds, and are fixed in Workstation 26H1u1 and Fusion 26H1u1. No in-the-wild exploitation has been observed, though VMware vCenter flaws CVE-2026-59309 and CVE-2026-59310, the latter suspected of China-nexus APT use, have recently breached 361 unique victim IPs across 47 countries.

Microsoft Patches Record 974 Vulnerabilities, Including Two Exploited Zero-Days

Microsoft's September 2026 Patch Tuesday fixes a record 974 CVEs, including two Windows zero-days exploited in the wild for privilege escalation.

Microsoft patched 974 vulnerabilities, its largest Patch Tuesday ever, including CVE-2026-85880, a heap buffer overflow in Windows ALPC allowing AppContainer sandbox escape to System, and CVE-2026-81963, a link-following flaw in the Windows Update Stack enabling local privilege escalation. Both were exploited as zero-days before the patch. ZDI's Dustin Childs says 20 of the fixed flaws are wormable, enabling unauthenticated remote code execution. The release also covers 723 Windows flaws and 222 Office bugs, plus fixes in Exchange, SharePoint, SQL Server, Azure and Exchange Server RCE (CVE-2026-55007).

SecurityWeek · 8d agoExploit / PoC in the wildCVE-2026-85880CVE-2026-81963CVE-2026-55007+5 CVEs1

Windows Remote Desktop Client Vulnerability Allows Attackers to Execute Remote Code

Microsoft patched CVE-2026-69485, an 8.8 CVSS RCE flaw in the Windows Remote Desktop Client affecting Windows 10/11 and Server 2016-2025.

Microsoft's September 2026 updates fix CVE-2026-69485, an Important-rated remote code execution vulnerability (CVSS 3.1: 8.8, temporal 7.7) in the Windows Remote Desktop Client caused by use of an uninitialized resource. An authenticated attacker with low privileges could send a specially crafted network request to execute code on an affected server, with no user interaction required. Microsoft says the flaw was not publicly disclosed before patching and rates exploitation as 'Less Likely' with no evidence of active exploitation. Affected products span Windows Server 2016, 2019, 2022 and 2025 and Windows 10 (1607-22H2) and Windows 11 (23H2-26H1), with fixes delivered via KBs including KB5123099, KB5122876 and KB5122882.

ConnectWise Patches ScreenConnect Vulnerability Exploited in Worm-Like Attacks

ConnectWise patched critical ScreenConnect flaw CVE-2026-84869 (CVSS 9.9) exploited since August 20 in worm-like attacks; CISA added it to KEV.

ConnectWise released urgent patches for CVE-2026-84869 (CVSS 9.9), a missing authorization and improper privilege management flaw in ScreenConnect allowing file transfer and execution through active remote sessions without host confirmation. Huntress reported in-the-wild exploitation since August 20, with attackers using rogue ScreenConnect clients to push four VBScript files for persistence and worm-like propagation to other ScreenConnect clients. The flaw is fixed in ScreenConnect 26.6.5, with disabling the TransferFiles permission as a temporary mitigation. CISA added the CVE to its KEV catalog, requiring federal agencies to patch within three days under BOD 26-04.

SecurityWeekupdated · 11h agofirst · 2d agoExploit / PoC in the wild 4 sourcesCVE-2026-848691

The Apple Security Update Review for September 2026

Apple's September 2026 updates patch 45+ flaws, including a 9.8 Screen Sharing authentication bypass (CVE-2026-65400) already listed in CISA's KEV.

ZDI's review of Apple's September 2026 security updates catalogs dozens of CVEs across macOS, iOS, iPadOS, watchOS and other platforms. CVE-2026-65400 (CVSS 9.8) lets a network attacker authenticate to Screen Sharing Server without valid credentials and is flagged as KEV, while CVE-2026-65414 (CVSS 9.8) enables remote code execution via Bluetooth. The set also includes 8.8-rated memory corruption flaws in WebKit, WebRTC, CUPS, ImageIO and the kernel, plus sandbox escapes, privilege escalations to root, and arbitrary code execution via crafted files.

Microsoft fixes record 964 flaws, including 2 exploited zero-days

Microsoft's September Patch Tuesday fixes a record 964 CVEs, including two actively exploited Windows privilege-escalation zero-days, CVE-2026-81963 and CVE-2026-85880.

Microsoft's September 2026 Patch Tuesday addresses 964 customer-patchable CVEs (104 Critical, 860 Important), the largest release on record, out of 974 total listed. Two actively exploited zero-days are fixed: CVE-2026-81963, a link-following elevation-of-privilege flaw in the Windows Update Stack, and CVE-2026-85880, a Windows ALPC heap overflow enabling AppContainer sandbox escape, both with CVSS 7.8. Both zero-days were exploited before a patch was available and grant SYSTEM-level access after an initial foothold. The release also includes high-severity RCE fixes for Windows DNS Server, Remote Desktop Services, Exchange Server, SharePoint, and SQL Server.

Malwarebytes Labs · 7d agoExploit / PoC in the wildCVE-2026-81963CVE-2026-858801

Microsoft Shatters Patch Tuesday Record With 974 CVE Fixes in September 2026

Microsoft's September 2026 Patch Tuesday fixes a record 974 CVEs, including two actively exploited Windows zero-days, CVE-2026-85880 and CVE-2026-81963.

Microsoft fixed a record 974 CVEs in its September 2026 Patch Tuesday, surpassing the previous record of 570 in July 2026, with Windows affected by 723 flaws and Office by 111, including 119 critical vulnerabilities. Two zero-days are actively exploited: CVE-2026-85880, a 7.8 heap-based buffer overflow in Windows ALPC allowing AppContainer privilege escalation, and CVE-2026-81963, an improper link resolution flaw in the Windows Update Stack enabling local privilege escalation. Microsoft attributed the update surge partly to agentic AI tools used to discover zero-day vulnerabilities, and researchers highlighted critical RCE flaws in Windows DNS, DHCP and Deployment Services as priorities.