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.
SAP Commerce Cloud CVE-2026
Attackers actively exploit unauthenticated RCE CVE-2026-58231 (CVSS 10.0) in SAP Commerce Cloud days after patch release.
CVE-2026-58231, a maximum-severity flaw in SAP Commerce Cloud (CVSS 10.0), allows unauthenticated attackers to abuse a default authentication client and bypass insufficient validation, achieving arbitrary code execution and compromise of internal components. Defused Cyber researchers observed exploitation attempts against honeypots only three days after SAP released the patch. The flaw had no public PoC and was not previously known to be exploited. The attackers are unknown, though past critical SAP flaws have been exploited by China-linked groups UNC5221 and UNC5174 and ransomware gangs.
SAP Commerce Cloud CVE-2026-58231 Targeted in Exploitation Attempts Days After Patch
A maximum-severity (CVSS 10.0) unauthenticated RCE flaw in SAP Commerce Cloud, CVE-2026-58231, is under active exploitation days after patching.
CVE-2026-58231, rated 10.0 on CVSS, stems from insufficient authorization checks and input validation in SAP Commerce Cloud, enabling unauthenticated arbitrary code execution. Defused Cyber's honeypots detected exploitation attempts three days after the patch, and KEVIntel independently confirmed two attempts on August 14 from a US IP address. Onapsis urges customers to patch and rebuild, with an IP Filter Set offered as a temporary workaround. No actor attribution yet, though prior SAP NetWeaver flaw CVE-2025-31324 was exploited by China-nexus and criminal groups.