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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.

Zscaler ThreatLabz · 13d agoVulnerabilityCVE-2026-629112

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.

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

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.

The Hacker News · Aug 11, 2026Malware in the wild

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.

Help Net Security · 20d agoExploit / PoC in the wildCVE-2026-8452CVE-2015-3246CVE-2015-5287+3 CVEs

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.

Details emerge on BlackFile's recent attacks on financial companies

BlackFile (UNC6671), a The Com-linked extortion crew, keeps hitting financial and med tech firms with voice-phishing IT-support scams and ~$3 million demands.

Google Threat Intelligence Group (tracking BlackFile as UNC6671, linked to The Com) reports the extortion group remains active, shifting focus to the financial sector and med tech organizations, with new Redact-brand extortion demands issued last week. The group impersonates IT support in voice-phishing attacks using hundreds of recruited callers, targets large firms in what researchers call big-game hunting, and processes an average of 1.5 new victims daily. Extortion demands start around $3 million and are typically negotiated below $1 million; Flashpoint observed infrastructure targeting Blackstone, Bain Capital, Moody's, CME, and Apollo, though compromise is unconfirmed. Mandiant has responded to more than two dozen BlackFile compromises since January, and victims face escalation tactics including swatting.

CyberScoop · Aug 17, 2026Threat actor in the wild

Microsoft’s massive Patch Tuesday releases continue as AI reshapes bug discovery

Microsoft patches 419 vulnerabilities in record-breaking Patch Tuesday; Windows Winsock zero-day CVE-2026-68820 is actively exploited by Lazarus Group.

Microsoft's August Patch Tuesday fixes 419 vulnerabilities (62 critical, 357 important), among the largest monthly counts on record, following 206 fixes in June and 622 in July as AI-assisted discovery drives unprecedented volume. Three flaws are zero-days; Windows Winsock bug CVE-2026-68820 is exploited in the wild by Lazarus Group in job-themed attacks using PDFs with a trojanised reader. CVE-2026-62832, publicly disclosed by researcher Nightmare Eclipse via the LegacyHive PoC, is also patched. Microsoft now lists bugs by product family instead of itemized CVEs, which defenders warn complicates triage.

The Record · Aug 12, 2026Vulnerability in the wildCVE-2026-68820CVE-2026-62832

Berlin Refuses to Pay Hackers Who Stole Data From the City's State Network

Berlin refuses ransom demands after Rhysida claimed stealing 5.79 TB from the city-state network, including mobility department data on 12,076 individuals.

Berlin's state government confirmed an extortion attempt following the August compromise of its state administrative network and said it will not pay. Forensics found data exfiltrated from the Senate Department for Mobility, Transport, Climate Protection and Environment between August 7 and 12, 2026; Rhysida's leak site claims 5.79 TB, 1.44 million files, and personal data on 12,076 individuals. State criminal police, prosecutors, and federal authorities are investigating, and officials say the September 20 Abgeordnetenhaus election environment remains unaffected. Separately, Manchester Airports Group confirmed theft of customer data including emails, phone numbers, and vehicle registrations across three airports.

The Hacker News · 19d agoRansomware in the wildCVE-2020-1472

Microsoft patches 400+ vulnerabilities, one zero-day under attack (CVE-2026-68820)

Microsoft's August 2026 Patch Tuesday fixes 400+ vulnerabilities, including an actively exploited Windows zero-day (CVE-2026-68820) used by North Korean attackers.

Microsoft's August 2026 Patch Tuesday fixes over 400 vulnerabilities, including CVE-2026-68820, a use-after-free in the Windows Ancillary Function Driver exploited in the wild by North Korean actors deploying a kernel-mode rootkit in Operation Dream Job. Critical unauthenticated remote code execution flaws in Microsoft QUIC (CVE-2026-62815) and Windows DNS (CVE-2026-62878) were also patched, alongside a SharePoint RCE chain combining CVE-2026-63520 with CVE-2026-55040. Researcher Nightmare-Eclipse released ShieldBreak, a PoC bypassing the July RoguePlanet Microsoft Defender patch (CVE-2026-50656), confirmed working by Will Dormann on Windows 11.

Help Net Security · Aug 12, 2026Exploit / PoC in the wildCVE-2026-68820CVE-2026-62832CVE-2026-72971+6 CVEs

Critical NetScaler Flaw Can Bypass Authentication on Certain Gateway and AAA Servers

Citrix patches critical NetScaler Gateway and AAA authentication bypass CVE-2026-19490 (CVSS 9.3) plus a SIP ALG memory overflow flaw; exploitation attempts observed.

Citrix fixed CVE-2026-19490 (CVSS 9.3), an authentication bypass affecting customer-managed NetScaler ADC and Gateway appliances configured as Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual servers, and CVE-2026-19489 (CVSS 8.8), a memory overflow causing DoS when SIP ALG is enabled in Large Scale NAT groups. Updates are available in versions 14.1-73.32, 13.1-63.21, and corresponding FIPS/NDcPP builds, while Citrix-managed cloud services were already patched. The flaws were reported by Samarth Vashisht of JPMorgan Chase's penetration-testing team, and Previdian later observed 10 exploitation attempts against CVE-2026-19490 from six unique IP addresses in Australia, Germany, Japan, and the US, with no confirmed compromise.

Cisco Nexus 9000 Series Switches Silicon One Remote Code Execution Vulnerability

Cisco patches unauthenticated RCE in Nexus 9000 Silicon One switches exposed via TCP ports 43210 and 43211 in the default L3 VRF.

Cisco disclosed and patched a vulnerability in the Silicon One integration for Nexus 9000 Series switches that allows an unauthenticated remote attacker to execute code with root privileges. The flaw stems from TCP ports 43210 and 43211 being accessible in the default Layer 3 VRF. Exploitation can also crash the S1HAL process and force an affected device to reload. Cisco has released software updates, and workarounds are available to mitigate exposure.

Cisco Security Advisories · 14d agoVulnerability