August Microsoft Patch Tuesday. A total of 401 vulnerabilities were addressed - 170 fewer than in July. One of the vulnerabilities is known to be actively exploited in the wild:
🔻 EoP - Windows Ancillary Function Driver for WinSock (CVE-2026-68820). A local attacker can exploit this vulnerability to gain SYSTEM-level privileges. There is a contradiction in Microsoft's description: the Exploit Code Maturity in CVSS is marked as "Unproven", while at the same time Microsoft states that the vulnerability is being exploited in the wild. 🤷♂️
Public exploits are available for two other vulnerabilities:
🔸 EoP - Windows User Profile Service (CVE-2026-62832). This vulnerability allows an authenticated attacker to elevate privileges to ADMINISTRATOR level. Rapid7 believes this vulnerability is related to the LegacyHive exploit, which was published on July 14.
🔸 EoP - Windows Kernel (CVE-2026-62737). This vulnerability allows an authenticated attacker to elevate privileges to SYSTEM level. An exploit has been publicly available since August 11.
Among the remaining vulnerabilities, the following stand out:
🔹 RCE - Windows DNS Server (CVE-2026-62878). This wormable vulnerability allows a remote unauthenticated attacker to execute code on a vulnerable server with elevated privileges. It is recommended to test and install the update as soon as possible, especially on Internet-facing DNS servers.
🔹 RCE - Windows Deployment Services TFTP Server (CVE-2026-62893). This vulnerability, discovered as part of the ZDI (Zero Day Initiative) program, allows an attacker to execute code without authentication or user interaction. TFTP has no authentication mechanism and is available remotely via UDP port 69. Any WDS server serving Windows Imaging Format (WIM) files via TFTP, which is the standard PXE boot scenario, is vulnerable. The issue results from the lack of validation of the existence of an object before performing operations on it. UDP port 69 should be blocked at the perimeter, but attackers could easily use this vulnerability for lateral movement within an organization. If you're using WDS for deployments, test and install this update quickly.
🔹 RCE - Windows DHCP Server (CVE-2026-62823). Successful exploitation of this vulnerability allows a remote unauthenticated attacker to execute arbitrary code from an adjacent network by sending a specially crafted packet that triggers a heap-based buffer overflow.
🔹 EoP - Microsoft Exchange (CVE-2026-62911). This vulnerability allows a remote authenticated attacker (with Privileges Required: Low according to CVSS) to gain control over the mailboxes of all Exchange users, send and read emails, and download attachments. This vulnerability was demonstrated at Pwn2Own Berlin. ZDI researchers provided Microsoft with working exploits.
🔹 RCE - Microsoft QUIC (CVE-2026-62815). This use-after-free vulnerability allows an unauthenticated attacker to execute arbitrary code on a target system by sending a specially crafted network packet. QUIC is an IETF-standardized transport protocol that runs over UDP instead of TCP and serves as the foundation for HTTP/3. The protocol is used by approximately 13.5 million websites.
🔹 Tampering - Windows Container Isolation FS Filter Driver (unionfs.sys) (CVE-2026-72971). This vulnerability reportedly allows an attacker to overwrite certain files. As a result, an attacker could perform an action within a container that could impact the host system.
