Microsoft shipped emergency out-of-band fixes to correct glitches from a record Patch Tuesday covering nearly 1,000 CVEs.
Dark Reading reports that Microsoft issued emergency fixes following a massive Patch Tuesday that addressed nearly 1,000 CVEs. The out-of-band updates correct glitches introduced by the record-sized monthly release. The brief excerpt names no specific CVEs, affected products, or actively exploited flaws.
Microsoft's September 2026 Patch Tuesday updates (KB5124008) can break Remote Desktop Services, causing RDP failures and freezes across Windows clients and servers.
Microsoft confirmed its September 2026 security updates, including KB5124008 for Windows 11 24H2/25H2, introduced a reliability regression where RDP connections fail after several minutes and servers hang at the 'Please wait for the Remote Desktop Configuration' screen. MMC, RDS Licensing Diagnoser, File Explorer, and the Windows Update settings page may also stop responding. The issue affects Windows 10/11 clients and Windows Server 2012 through 2025; Microsoft marked it Mitigated on September 11 and is developing a permanent fix, with VM restart offered as a temporary workaround.
Microsoft confirms September 2026 Patch Tuesday updates break Remote Desktop Services on Windows Server 2012+; Group Policy mitigations and rollback workarounds available.
Microsoft confirmed that September 2026 Patch Tuesday security updates cause Remote Desktop Services failures on Windows Server 2012 and later, plus Windows 10 and Windows 11. Symptoms include unstable RDS, RDP connection failures after several minutes, sign-in issues, servers hanging at 'Please wait for the Remote Desktop Configuration,' and unresponsive MMC, RDS Licensing Diagnoser, and File Explorer. Microsoft published per-version Group Policy mitigations (covering KBs such as KB5124008, KB5122880, KB5122878, KB5122871, KB5122882, KB5122876, KB5123099, KB5123065, KB5123066) and suggests restarting affected VMs. Rolling back the updates restores RDS functionality but removes this month's security fixes.
Microsoft confirms KB5002914 Excel security update silently breaks copy-paste in Excel 2016-2024, forcing admins to choose between usability and security fixes.
Microsoft added a known issue to KB5002914, the September 8, 2026 Excel security update, where paste, autofill, and formula dragging fail silently with no error in Excel 2016, 2019, 2021, and 2024. The update addresses remote code execution and information disclosure flaws including CVE-2026-81399, CVE-2026-81390, and CVE-2026-81954. No hotfix date has been published as of September 15, 2026; the only widely confirmed recovery is uninstalling or rolling back KB5002914, which drops the month's Excel security fixes.
JFrog disclosed CVE-2026-90894, a 7.8-rated local privilege escalation in Parallels Desktop for Mac, patched only in version 27, which Intel Macs cannot install.
JFrog researcher Yuval Moravchick disclosed CVE-2026-90894 (dubbed ParaShells, CVSS 7.8), a local privilege escalation in Parallels Desktop for Mac that lets non-admin users run code as root. The root-level prl_disp_service listens on a world-writable socket, and argument injection into a tar command via QProcess::splitCommand and the --use-compress-program option yields code execution as root, demonstrated on Parallels Desktop 26.4.0 build 57513 on Apple silicon. The fix appears in version 27.0.0, but Parallels Desktop 27 requires Apple silicon, leaving Intel Macs on the 26.x line with no build JFrog describes as fixed. No exploitation in the wild has been reported and Parallels has not published a statement.