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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.

Cisco Talos · 7d agoAdvisory in the wildCVE-2026-81963CVE-2026-85880CVE-2026-69676+27 CVEs

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 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

Google Chrome 153 Released With 230 Security Fixes and Zero-Day Exploited in the Wild

Google released Chrome 153 with 230 security fixes, patching CVE-2026-87491, a V8 out-of-bounds write zero-day actively exploited in the wild.

Google shipped Chrome 153 (153.0.8010.36/.37) for Windows, macOS, and Linux with 230 security fixes, including CVE-2026-87491, a medium-severity V8 out-of-bounds write being exploited in the wild. The release also fixes five critical vulnerabilities: four in WebGL (two use-after-frees, an out-of-bounds write, a buffer overflow) and one use-after-free in Cast. High-severity V8 use-after-free and type-confusion defects are among the fixes, and Google has restricted technical details until most users are patched. Administrators should verify deployed versions on managed endpoints, as Chrome-derived browsers may follow different patch schedules.

GBHackers · 7d agoExploit / PoC in the wildCVE-2026-87491CVE-2026-87464CVE-2026-87488+19 CVEs1

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.

CISA Adds Four Known Exploited Vulnerabilities to Catalog

CISA added four actively exploited vulnerabilities—Fortinet buffer overflow, Citrix NetScaler and Cisco auth bypasses, and a Chromium V8 write—to the KEV Catalog.

CISA added CVE-2025-25249 (Fortinet heap-based buffer overflow), CVE-2026-19490 (Citrix NetScaler authentication bypass), CVE-2026-87491 (Google Chromium V8 out-of-bounds write), and CVE-2026-20079 (Cisco Firewall Management Center authentication bypass) to its Known Exploited Vulnerabilities Catalog based on evidence of active exploitation. Under Binding Operational Directive 26-04, Federal Civilian Executive Branch agencies must prioritize rapid remediation of these high-risk vulnerabilities on exposed assets and verify whether systems were compromised before patching. CISA encourages all organizations to adopt risk-based vulnerability management and prioritize KEV Catalog remediation.

CISA Advisories · 7d agoExploit / PoC in the wildCVE-2025-25249CVE-2026-19490CVE-2026-87491+1 CVEs

Fortinet Code Execution Flaw Exploited in PivotC2 RAT Attacks

Threat actors exploit Fortinet heap-based buffer overflow CVE-2025-25249 to deploy PivotC2 RAT, infecting 178 devices and exfiltrating data from US targets.

SOCRadar reports exploitation of an unauthenticated remote code execution vulnerability, CVE-2025-25249 (CVSS 7.4), patched in January in FortiOS and FortiSwitchManager. Attackers scanned over 30,000 IP addresses, infected 178 devices with PivotC2 RAT, and at least two intrusions resulted in data exfiltration, primarily targeting US entities. SOCRadar attributes attacks to a likely Russian-speaking cybercrime actor and suggests the RAT was AI-assisted, in use since July 2026. CISA added the CVE to the KEV catalog with a three-day BOD 26-04 patch deadline for federal agencies.

SecurityWeekupdated · 6d agofirst · 6d agoExploit / PoC in the wild 4 sourcesCVE-2025-252491