47
42
42
42
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.
84
42
57
47
60
42
57
Nearly 800 Malicious npm Packages Deliver Cross
Nearly 800 typo-squatted npm packages deliver WEL1DROPPER, a cross-platform downloader installing RAT and infostealer payloads on Windows, macOS, Linux.
Researchers found roughly 800 npm packages with AI-generated typo-squat names that trigger a WEL1DROPPER downloader when loaded via require() rather than install hooks. The downloader fetches payloads from Cloudflare Workers hosts, falling back to DNS TXT records from wel1.ru, then achieves persistence, sandbox checks, ETW/AMSI patching and Sliver C2 deployment on Linux. Domains like tcsbank.ru suggest targeting of Russian financial institutions; Sonatype tracks the campaign as Flooding Dropper, a possible evolution of the Moika dependency-confusion campaign. Unit 42 separately documented npm/PyPI crypto stealers and malicious Chrome extensions that turn browsers into residential proxy crawlers.
72
Previously patched Citrix NetScaler flaw exploited in the wild (CVE-2026-8452)
Actively exploited Citrix NetScaler flaw CVE-2026-8452, patched in June, now added to CISA KEV; attackers deploy web shells and run discovery commands.
CISA added CVE-2026-8452, a memory overflow vulnerability in Citrix NetScaler ADC/Gateway, to its Known Exploited Vulnerabilities catalog on August 26, 2026, giving federal agencies until August 29 to remediate. Citrix disclosed and patched the flaw on June 30, 2026 in versions 14.1-72.61, 13.1-63.18, and 13.1-37.272. watchTowr Labs found the flaw can be chained into unauthenticated remote code execution and released a PoC on August 14. Previdian and Defused reported exploitation with web shells named x.php and z.php from at least three unique source IPs.
82
42
57
60
60
60
60
47
60
42
Oracle Critical Security Patch Update, September 2026 Review
Oracle's September 2026 Critical Patch Update fixes 673 vulnerabilities, including 104 critical, with many remotely exploitable in E-Business Suite and Fusion Middleware.
Oracle released 673 security patches in its September 2026 Critical Patch Update: 104 rated critical, 503 high, and 59 medium. Oracle E-Business Suite received the most patches (159, 24% of total), with 19 exploitable without credentials including CVE-2026-83327, CVE-2026-83452, and CVE-2026-83462 at CVSS 9.8. Fusion Middleware received 153 patches with 78 remotely exploitable without authentication, and 41 patches address third-party open-source component flaws. Qualys published detection QIDs for vulnerable assets.
55
Three Critical VMware Flaws Allow Auth Bypass, Code Execution, and VM Escape
Broadcom patches three critical VMware flaws, including vCenter auth bypass CVE-2026-59309 and an ESX VM escape, urging immediate updates.
Broadcom issued emergency updates for VMware ESX, vCenter, Workstation and Fusion, fixing five flaws including CVE-2026-59309 (CVSS 9.8 authentication bypass in vCenter) and CVE-2026-59310 (CVSS 9.8 directory traversal allowing code execution). CVE-2026-47876 (CVSS 9.3) is an out-of-bounds write in the ESX VMXNET3 adapter that permits a virtual machine escape to the host. Broadcom found no evidence of exploitation, but Defused Cyber reported a spike in vCenter scanning on August 11, 2026 consistent with exploitation attempts against CVE-2026-59309 (VMSA-2026-0006). No workarounds are available.
80
42
42
47
42
60
42
47
60
47
47
60
60
42
47
42
47