From 3874cae47fcc0d593e3072833d1509a0f6892daf Mon Sep 17 00:00:00 2001 From: Tara Overfield Date: Thu, 3 Sep 2026 21:12:31 -0700 Subject: [PATCH 1/3] publish 9B release notes --- .../2026/09-08-september-cumulative-update.md | 85 +++++++++++++++++++ docs/framework/release-notes/release-notes.md | 3 +- docs/framework/toc.yml | 2 + 3 files changed, 89 insertions(+), 1 deletion(-) create mode 100644 docs/framework/release-notes/2026/09-08-september-cumulative-update.md diff --git a/docs/framework/release-notes/2026/09-08-september-cumulative-update.md b/docs/framework/release-notes/2026/09-08-september-cumulative-update.md new file mode 100644 index 0000000000000..71cc638254512 --- /dev/null +++ b/docs/framework/release-notes/2026/09-08-september-cumulative-update.md @@ -0,0 +1,85 @@ +--- +title: September 2026 cumulative update +description: Learn about the improvements in the .NET Framework September 2026 cumulative update. +ms.date: 09/08/2026 +ai-usage: ai-generated +--- +# .NET Framework August 2026 cumulative update + +_Released September 8, 2026_ + +## Summary of what's new in this release + +- [Security improvements](#security-improvements) +- [Quality and reliability improvements](#quality-and-reliability-improvements) + +### Security improvements + +#### CVE-2026-62886 – Elevation of Privilege vulnerability + +This security update addresses an elevation of privilege vulnerability detailed in [CVE-2026-62886.](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62886) + +#### CVE-2026-69522 – Remote Code Execution vulnerability + +This security update addresses a remote code execution vulnerability detailed in [CVE-2026-69522.](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69522) + +### Quality and reliability improvements + +There are no new quality and reliability improvements in this release. + +## Known issues in this release + +Microsoft is not currently aware of any issues in this update. + +## Summary tables + +The following table outlines the updates in this release. + +| Product version | Cumulative update | +| --- | --- | +| **Windows 11, version 26H1** | | +| .NET Framework 4.8.1 | [5126053](https://support.microsoft.com/kb/5126053) | +| **Windows 11, version 25H2** | | +| .NET Framework 3.5, 4.8.1 | [5126052](https://support.microsoft.com/kb/5126052) | +| **Windows 11, version 24H2** | | +| .NET Framework 3.5, 4.8.1 | [5126052](https://support.microsoft.com/kb/5126052) | +| **Windows 11, version 23H2** | | +| .NET Framework 3.5, 4.8.1 | [5126424](https://support.microsoft.com/kb/5126424) | +| **Windows Server 2025** | | +| .NET Framework 3.5, 4.8.1 | [5126052](https://support.microsoft.com/kb/5126052) | +| **Windows Server 2022** | | +| .NET Framework 3.5, 4.8 | [5126050](https://support.microsoft.com/kb/5126050) | +| .NET Framework 3.5, 4.8.1 | [5126422](https://support.microsoft.com/kb/5126422) | +| **Windows 10, version 22H2** | | +| .NET Framework 3.5, 4.8 | [5126046](https://support.microsoft.com/kb/5126046) | +| .NET Framework 3.5, 4.8.1 | [5126421](https://support.microsoft.com/kb/5126421) | +| **Windows 10, version 21H2** | | +| .NET Framework 3.5, 4.8 | [5126046](https://support.microsoft.com/kb/5126046) | +| .NET Framework 3.5, 4.8.1 | [5126421](https://support.microsoft.com/kb/5126421) | +| **Windows 10 1809 and Windows Server 2019** | | +| .NET Framework 3.5, 4.7.2 | [5126043](https://support.microsoft.com/kb/5126043) | +| .NET Framework 3.5, 4.8 | [5126048](https://support.microsoft.com/kb/5126048) | +| **Windows 10 1607 and Windows Server 2016** | | +| .NET Framework 3.5, 4.6.2, 4.7, 4.7.1, 4.7.2 | Pending package; will be included in the LCU | +| .NET Framework 4.8 | [5126047](https://support.microsoft.com/kb/5126047) | + +The following table is for earlier Windows Server versions for Security and Quality Rollup updates. + +| Product version | Security and quality rollup | +| --- | --- | +| **Windows Server 2012 R2** | | +| .NET Framework 3.5 | [5120695](https://support.microsoft.com/kb/5120695) | +| .NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 | [5126045](https://support.microsoft.com/kb/5126045) | +| .NET Framework 4.8 | [5126051](https://support.microsoft.com/kb/5126051) | +| **Windows Server 2012** | | +| .NET Framework 3.5 | [5120716](https://support.microsoft.com/kb/5120716) | +| .NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 | [5126044](https://support.microsoft.com/kb/5126044) | +| .NET Framework 4.8 | [5126049](https://support.microsoft.com/kb/5126049) | + +The operating system rows list a KB that's used for update-offering purposes. When the operating system KB is offered, the applicability logic determines the specific .NET Framework updates that will be installed. Updates for individual .NET Framework versions are installed based on the version of .NET Framework that's already present on the device. Because of this, the operating system KB is not expected to be listed as an installed update on the device. The expected updates to be installed are the .NET Framework specific version updates listed in the preceding table. + +This update installs the complete .NET Framework 3.5 product for Windows 11, version 26H1 (build version 28000) and newer. Unlike traditional cumulative updates that patch individual components, this update delivers the full .NET Framework 3.5 product as a standalone installer. It replaces any previously installed version. + +| Product version | .NET Framework 3.5 product update | +| --- | --- | +| .NET Framework 3.5 | [5120747](https://support.microsoft.com/kb/5120747) | diff --git a/docs/framework/release-notes/release-notes.md b/docs/framework/release-notes/release-notes.md index 1fc8f7fff02fe..1c471bd74f1c6 100644 --- a/docs/framework/release-notes/release-notes.md +++ b/docs/framework/release-notes/release-notes.md @@ -11,7 +11,8 @@ The .NET Framework updates include cumulative security and reliability improveme .NET Framework cumulative update releases are discussed in detail in the following individual release notes: -* August 27, 2026 - [cumulative update preview](./2026/08-27-august-cumulative-update-preview.md) **New Release** +* September 8, 2026 - [cumulative update](./2026/09-08-september-cumulative-update.md) **New Release** +* August 27, 2026 - [cumulative update preview](./2026/08-27-august-cumulative-update-preview.md) * August 11, 2026 - [cumulative update](./2026/08-11-august-cumulative-update.md) * July 14, 2026 - [cumulative update](./2026/07-14-july-cumulative-update.md) * May 26, 2026 - [cumulative update preview](./2026/05-26-may-cumulative-update-preview.md) diff --git a/docs/framework/toc.yml b/docs/framework/toc.yml index d37c85a679de3..b55abb504d89e 100644 --- a/docs/framework/toc.yml +++ b/docs/framework/toc.yml @@ -679,6 +679,8 @@ items: items: - name: Overview and index href: release-notes/release-notes.md + - name: September 2026 cumulative update + href: release-notes/2026/09-08-september-cumulative-update.md - name: August 2026 cumulative update preview href: release-notes/2026/08-27-august-cumulative-update-preview.md - name: August 2026 cumulative update From 5e0e0f785885deae6cfaff06aa4409531d6dead6 Mon Sep 17 00:00:00 2001 From: Tara Overfield Date: Fri, 4 Sep 2026 19:28:54 -0700 Subject: [PATCH 2/3] Update release notes for September 2026 update Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> --- .../release-notes/2026/09-08-september-cumulative-update.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/framework/release-notes/2026/09-08-september-cumulative-update.md b/docs/framework/release-notes/2026/09-08-september-cumulative-update.md index 71cc638254512..57dc3f766dd3a 100644 --- a/docs/framework/release-notes/2026/09-08-september-cumulative-update.md +++ b/docs/framework/release-notes/2026/09-08-september-cumulative-update.md @@ -4,7 +4,7 @@ description: Learn about the improvements in the .NET Framework September 2026 c ms.date: 09/08/2026 ai-usage: ai-generated --- -# .NET Framework August 2026 cumulative update +# .NET Framework September 2026 cumulative update _Released September 8, 2026_ From 566dcc6f81647ba90205ab3d25d5ff4eb72139ae Mon Sep 17 00:00:00 2001 From: Tara Overfield Date: Fri, 4 Sep 2026 19:29:31 -0700 Subject: [PATCH 3/3] Fix formatting of CVE-2026-62886 description Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> --- .../release-notes/2026/09-08-september-cumulative-update.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/framework/release-notes/2026/09-08-september-cumulative-update.md b/docs/framework/release-notes/2026/09-08-september-cumulative-update.md index 57dc3f766dd3a..e4fd813251ef4 100644 --- a/docs/framework/release-notes/2026/09-08-september-cumulative-update.md +++ b/docs/framework/release-notes/2026/09-08-september-cumulative-update.md @@ -17,7 +17,7 @@ _Released September 8, 2026_ #### CVE-2026-62886 – Elevation of Privilege vulnerability -This security update addresses an elevation of privilege vulnerability detailed in [CVE-2026-62886.](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62886) +This security update addresses an elevation of privilege vulnerability detailed in [CVE-2026-62886](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62886). #### CVE-2026-69522 – Remote Code Execution vulnerability