Microsoft Exchange Vulnerability CVE-2026-62911: What Administrators Should Do and How Zscaler Can Help
High-severity authentication bypass CVE-2026-62911 in Exchange Server has public exploit code; about 22,000 servers remain unpatched and internet-exposed.
Microsoft's August 2026 Patch Tuesday fixed CVE-2026-62911 (CVSS 8.0), an authentication bypass affecting Exchange Server 2016, 2019 and Subscription Edition. Successful exploitation lets an attacker with basic privileges take over all mailboxes on the targeted server, including reading and sending email and downloading attachments. As of September 1, Shadowserver identified roughly 22,000 unpatched, internet-exposed Exchange servers, including about 6,200 in the US and 5,100 in Germany. NCSC-NL confirmed working exploit code is publicly available, while CISA has not yet reported exploitation in the wild.
Oracle Critical Security Update – 673 Vulnerabilities Patched Across Product Families
Oracle's September 2026 Critical Patch Update ships 673 patches across 17 product families, including 100+ critical and 240+ remotely exploitable flaws.
Oracle's September 2026 Critical Security Patch Update ships 673 patches covering 672 unique CVEs, with more than 130 additional CVEs resolved through bundled fixes, pushing the effective total past 800. Over 100 flaws are critical severity and more than 240 are remotely exploitable without authentication. Oracle E-Business Suite received 159 fixes, Fusion Middleware 153 (78 unauthenticated and network-exploitable), and Hyperion 102. No in-the-wild exploitation of these specific flaws is reported, but Oracle cites CISA's earlier 72-hour remediation order for actively exploited CVE-2026-21962 (CVSS 10.0).
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.
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.
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.