September 2026 Windows updates break RDS; Microsoft ships 14 Sep OOB fixes
UPDATE 14 September 2026 (BleepingComputer): Microsoft released emergency out-of-band updates that fix Remote Desktop Services failures introduced by the September 2026 security cumulatives, plus related Hyper-V Host Compute Service issues on some Windows 11 builds. OOB packages cited: Windows Server 2025 KB5129235, Server 2022 KB5129237, Server 2019 KB5129238; Windows 11 24H2/25H2 KB5129195, Windows 11 26H1 KB5129194; Windows 10 21H2/22H2 KB5129236 (plus related Win10 servicing packages such as KB5129238/9239 on older trains per Microsoft support links). Server OOBs via Microsoft Update Catalog; some client OOBs also via Windows Update / WSUS. USB audio regressions from September updates are not fully resolved by these OOBs. Prior desk state: Microsoft confirmed RDS instability on release health and published Known Issue Rollback Group Policy packages (e.g. Server 2025 KB5122871, Server 2022 KB5122882, Server 2019 KB5122876) while developing the permanent fix. Prefer the matching OOB over long-lived KIR or cumulative rollback. Operational advisory for AU Windows estates — distinct from Patch Tuesday CVE cards.
- Product
- Windows Remote Desktop Services / RDP (Server 2012+; Windows 10/11); Hyper-V HCS on some Win11
- Versions
- After September 2026 cumulatives including KB5122871 (Server 2025), KB5122882 (Server 2022), KB5124008 (Win11 24H2/25H2 + Server 2025 train) and related SKUs — apply matching 14 Sep OOB
- Exploited in Australia?
- unknown
- Patch to
- Install the matching 14 Sep 2026 OOB (KB5129235/9237/9238 server; KB5129195/9194/9236 client) from Windows Update/Catalog/WSUS; KIR remains a temporary alternative only if OOB cannot be staged
Primary: BleepingComputer — Microsoft emergency OOB for RDS (14 Sep 2026) · Vendor: Microsoft Windows release health — RDS after Sept 2026 update · BleepingComputer — Microsoft confirms RDS + KIR (earlier 14 Sep wire)