Microsoft Patch Tuesday, September 2026 Security Update Review
Microsoft's September 2026 Patch Tuesday fixes 974 vulnerabilities, including 113 critical and two actively exploited Windows privilege escalation flaws.
Microsoft's September 2026 Patch Tuesday fixes 974 vulnerabilities, its largest release ever, including 113 critical and 860 important, covering Windows HTTP.sys, Hyper-V, Entra ID, Exchange Server, Office, DNS, and more. Two zero-days are confirmed exploited in the wild: CVE-2026-81963 (Windows Update Stack EoP) and CVE-2026-85880 (ALPC heap overflow), both letting authenticated attackers gain SYSTEM privileges. Notable criticals include an Entra ID authentication bypass (CVE-2026-62916) and multiple Windows DNS Server and Office remote code execution flaws.
CISA Adds Six Exploited Flaws to KEV, Including NetScaler, Linux, and SQL Server Bugs
CISA added six actively exploited flaws to KEV, led by Citrix NetScaler CVE-2026-8452, with federal patch deadlines set.
CISA added six flaws to the KEV catalog on August 27, 2026, citing evidence of active exploitation, led by CVE-2026-8452, an improper buffer restriction in Citrix NetScaler ADC and Gateway that can cause denial-of-service. Defused Cyber and Previdian reported active exploitation of CVE-2026-8452, with 36 attempts over 12 days from 12 attacker IPs deploying web shells x.php and z.php. The other additions cover SQL Server RCE (CVE-2019-1068), Linux kernel out-of-bounds write (CVE-2022-0995), Red Hat ABRT and libuser privilege escalations (CVE-2015-5287, CVE-2015-3246), and AjaxPro deserialization RCE (CVE-2021-23758). FCEB agencies must patch CVE-2019-1068 and CVE-2026-8452 by August 29, 2026, and the rest by September 9, 2026.
Cisco Warns of Ongoing Exploitation of Critical Email Gateway Zero-Day
Cisco Secure Email Gateway zero-day CVE-2026-76461 (CVSS 9.8) is actively exploited for root command execution; CISA added it to KEV.
Cisco disclosed critical zero-day CVE-2026-76461 (CVSS 9.8) in Secure Email Gateway, remotely exploitable without authentication via crafted emails containing malicious SQL statements, leading to arbitrary command execution with root privileges. The flaw affects physical and virtual appliances regardless of configuration and has no workarounds. Cisco PSIRT confirmed active exploitation, and CISA added the CVE to its KEV catalog on September 14 with a federal remediation deadline of September 17. Admins should review mail_logs for suspicious SQL statements such as 'COPY.*TO PROGRAM'.
CVE-2019-1068: A remote code execution vulnerability exists in ...
CISA added CVE-2019-1068, a high-severity remote code execution flaw in Microsoft SQL Server, to its KEV catalog after confirming exploitation in the wild.
CVE-2019-1068 (CVSS 8.8, CWE-20) is an improper input validation flaw allowing unauthenticated RCE in Microsoft SQL Server 2014 SP2/SP3, 2016, and 2017 on 32-bit and x64 builds. Exploitation requires low complexity and low privileges with no user interaction, and CISA formally added it to the KEV catalog on August 26, 2026. The CVE was originally published on July 15, 2019 and carries an EPSS score of 52.8%. Administrators must inventory affected SQL Server assets and apply vendor patches on an accelerated timeline.
Microsoft security advisory – September 2026 monthly rollup (AV26-896) – Update 1
Canada's Cyber Centre relays Microsoft's September 2026 rollup; CISA added exploited zero-days CVE-2026-85880 and CVE-2026-81963 to KEV.
Advisory AV26-896 from the Canadian Centre for Cyber Security summarizes Microsoft's September 2026 monthly security rollup, listing affected products across Windows, Office, .NET, Azure, Exchange and SQL Server. It notes Microsoft confirmed CVE-2026-81963 and CVE-2026-85880 have been exploited. On September 8, 2026, CISA added both CVEs to its Known Exploited Vulnerabilities catalog, and administrators are urged to apply the updates.
Attackers Exploit Critical Switchvox Flaw to Deploy Reverse Shells Without Credentials
Attackers exploit unauthenticated SQL injection CVE-2026-9586 in Sangoma Switchvox to run PostgreSQL commands and deploy reverse shells.
Threat actors are exploiting CVE-2026-9586 (CVSS 9.3), an unauthenticated SQL injection in Sangoma Switchvox SMB Edition 8.3 (104997), since August 30, 2026, running arbitrary SQL as the PostgreSQL superuser and achieving remote code execution. The /pa endpoint concatenates the user-controlled PhoneIP value into PostgreSQL queries; attackers can extract database contents, escalate to Switchvox web administrator, exfiltrate the cookie signing key to forge authentication, and invoke reverse shells. Sangoma patched the flaw in Switchvox 8.4.0.2 on July 14, 2026, roughly 4,000 instances are internet-exposed (mostly in the US), and honeypot activity from IP 176.65.148.184 deploys reverse shells followed by Base64-encoded process enumeration.