Microsoft Patch Tuesday for August 2026 — Snort rules and prominent vulnerabilities
January 1, 2020 · Talos Intelligence · Severity: MEDIUM
Microsoft's August 2026 Patch Tuesday addresses 421 vulnerabilities, including 62 critical flaws and one actively exploited zero-day (CVE-2026-68820). Notable high-risk vulnerabilities include a critical RCE in Windows Deployment Services TFTP Server (CVSS 9.8) and critical RCEs in SharePoint Server and Windows DHCP Server. Organizations should prioritize patching the exploited privilege escalation flaw and the critical RCEs due to their potential for remote code execution without authentication.
Microsoft has released its monthly security update for August 2026, which includes 421 vulnerabilities affecting a range of products, including 62 that Microsoft marked as "critical."
Microsoft notes that 1 of the vulnerabilities disclosed this month have been exploited in the wild
CVE-2026-68820 is an elevation of privilege vulnerability affecting Windows Ancillary Function Driver for WinSock. A Use After Free vulnerability could allow an authorized attacker to elevate privileges locally. This vulnerability has a CVSS base score of 7.0.
Out of 62 "critical" vulnerabilities, 40 are remote code execution (RCE) vulnerabilities.
Microsoft considers exploitation of the following vulnerabilities more likely.
CVE-2026-62893 is a remote code execution vulnerability affecting Windows Deployment Services TFTP Server. A Use After Free could allow an unauthorized attacker to execute code over a network. This vulnerability has a CVSS base score of 9.8.
CVE-2026-65665 is a remote code execution vulnerability affecting Microsoft SharePoint Server. Deserialization of Untrusted Data could allow an authorized attacker to execute code over a network. This vulnerability has a CVSS base score of 8.8.
CVE-2026-62823 is a remote code execution vulnerability affecting Windows DHCP Server. A Heap-based Buffer Overflow could allow an unauthorized attacker to execute code over an adjacent network. This vulnerability has a CVSS base score of 8.8.
Microsoft considers exploitation of the following vulnerabilities less likely.
CVE-2026-62830 is an elevation of privilege vulnerability affecting Azure SRE Agent. Missing Authorization could allow an authorized attacker to elevate privileges over a network. This vulnerability has a CVSS base score of 9.9.
CVE-2026-50516 is an elevation of privilege vulnerability affecting Microsoft Azure Kubernetes Service. Missing Authentication for Critical Function could allow an unauthorized attacker to elevate privileges over a network. This vulnerability has a CVSS base score of 9.4.
Three remote code execution vulnerabilities, CVE-2026-68794, CVE-2026-68816 and CVE-2026-68804, affect Microsoft Excel and have a CVSS base score of 7.8. An unauthorized attacker could execute code locally. CVE-2026-68794 is a Heap-based Buffer Overflow. CVE-2026-68816 is a Stack-based Buffer Overflow. CVE-2026-68804 involves a Numeric Truncation Error and a Heap-based Buffer Overflow.
CVE-2026-62911 is an elevation of privilege vulnerability affecting Microsoft Exchange Server. Authentication Bypass by Capture-replay could allow an authorized attacker to elevate privileges over a network. This vulnerability has a CVSS base score of 8.0.
Nine remote code execution vulnerabilities, CVE-2026-63515, CVE-2026-65657, CVE-2026-63532, CVE-2026-64898, CVE-2026-64903, CVE-2026-64909, CVE-2026-64910, CVE-2026-64911 and CVE-2026-70130, affect Microsoft Office and could allow an unauthorized attacker to execute code locally. CVE-2026-63515 involves an Out-of-bounds Read and an Integer Underflow (Wrap or Wraparound) and has a CVSS base score of 7.8. CVE-2026-65657 is a Use After Free and has a CVSS base score of 7.8. CVE-2026-63532 involves an Integer Overflow or Wraparound and a Heap-based Buffer Overflow and has a CVSS base score of 7.8. CVE-2026-64898 involves a Heap-based Buffer Overflow and an Integer Overflow or Wraparound and has a CVSS base score of 7.8. CVE-2026-64903 involves an Integer Overflow or Wraparound and a Heap-based Buffer Overflow and has a CVSS base score of 7.8. CVE-2026-64909 involves an Integer Underflow (Wrap or Wraparound), an Out-of-bounds Read and a Heap-based Buffer Overflow and has a CVSS base score of 7.8. CVE-2026-64910 is an Untrusted Pointer Dereference and has a CVSS base score of 7.8. CVE-2026-64911 involves an Integer Overflow or Wraparound and a Heap-based Buffer Overflow and has a CVSS base score of 7.8. CVE-2026-70130 is a Heap-based Buffer Overflow and has a CVSS base score of 8.4.
Five remote code execution vulnerabilities, CVE-2026-63513, CVE-2026-63519, CVE-2026-65664, CVE-2026-63526 and CVE-2026-66807, affect Microsoft Office Graphics Component and have a CVSS base score of 7.8. An unauthorized attacker could execute code locally. CVE-2026-63513 is a Heap-based Buffer Overflow. CVE-2026-63519 is a Heap-based Buffer Overflow. CVE-2026-65664 is a Heap-based Buffer Overflow. CVE-2026-63526 is a Stack-based Buffer Overflow. CVE-2026-66807 is a Stack-based Buffer Overflow.
Three remote code execution vulnerabilities, CVE-2026-63518, CVE-2026-63525<
Key Takeaways
- 421 vulnerabilities patched, with 62 rated critical and 40 critical RCEs.
- CVE-2026-68820 (WinSock driver) actively exploited; prioritize immediate patching.
- CVE-2026-62893 (Windows TFTP Server) has a CVSS 9.8 and allows unauthenticated network RCE.
- CVE-2026-65665 (SharePoint Server) and CVE-2026-62823 (DHCP Server) are critical RCEs likely to be exploited.