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.NET Framework 3.5

.NET Framework 3.5

Every published release for .NET Framework 3.5, newest first: what each update changes, whether to install it and any confirmed known issues.

Latest
KB5127694 Oct 13, 2026
File version
2.0.50727.9188
Released
Nov 19, 2007
All editions
updates until Jan 9, 2029
Known issues
1 open

Update history

  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Security update
    Updated

    KB5120709

    Runtime vulnerabilities closed; WPF printing errors need later updates

    Closes six .NET Framework vulnerabilities, including three remote-code-execution flaws. Two WPF printing issues are resolved only in later updates.

    Check the newer update, KB5126421

    Key changes 6 CVEs · 6 changes

    • Fix .NET Framework: Closes an elevation-of-privilege vulnerability, CVE-2026-65810.
    • Fix .NET Framework: Closes an elevation-of-privilege vulnerability, CVE-2026-62872.
    • Fix .NET Framework: Closes a remote-code-execution vulnerability, CVE-2026-62886.

    Read update Source: Microsoft

    Builds
    4.8.9343.0 · 2.0.50727.9183
    Security
    6 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Security update
    Updated

    KB5120714

    Six runtime vulnerabilities addressed; WPF printing may fail

    Addresses six .NET Framework vulnerabilities, including remote-code-execution flaws. Some WPF apps may fail when printing or generating PDF/XPS content; later cumulative updates resolve the two listed issues.

    Check the newer update, KB5126422

    Key changes 6 CVEs · 6 changes

    • Fix .NET Framework: A .NET Framework elevation-of-privilege vulnerability is addressed.
    • Fix .NET Framework: A .NET Framework elevation-of-privilege vulnerability is addressed.
    • Fix .NET Framework: A .NET Framework remote-code-execution vulnerability is addressed.

    Read update Source: Microsoft

    Builds
    4.8.9343.0 · 2.0.50727.9183
    Security
    6 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Security update
    Updated

    KB5120701

    Code-execution and privilege flaws addressed

    Addresses six .NET Framework vulnerabilities, including flaws involving code execution, elevation of privilege, and information disclosure. Some WPF printing problems are resolved by later updates.

    Check the newer update, KB5126046

    Key changes 6 CVEs · 6 changes

    • Fix .NET Framework: Addresses a security flaw that could let an attacker gain higher privileges.
    • Fix .NET Framework: Addresses a security flaw that could let an attacker gain higher privileges.
    • Fix .NET Framework: Addresses a security flaw that could let an attacker run code.

    Read update Source: Microsoft

    Builds
    4.8.4805.0 · 2.0.50727.9183
    Security
    6 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Security update
    Updated

    KB5120705

    Six .NET vulnerabilities addressed; later updates fix WPF errors

    Addresses six .NET Framework vulnerabilities. Some WPF printing errors caused by the update are resolved in later updates.

    Check the newer update, KB5126050

    Key changes 6 CVEs · 6 changes

    • Fix .NET Framework: Addresses an elevation-of-privilege vulnerability in .NET Framework.
    • Fix .NET Framework: Addresses an elevation-of-privilege vulnerability in .NET Framework.
    • Fix .NET Framework: Addresses a remote code execution vulnerability in .NET Framework.

    Read update Source: Microsoft

    Builds
    4.8.4805.0 · 2.0.50727.9183
    Security
    6 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Security update
    Updated

    KB5120703

    Six runtime flaws addressed; WPF failures need newer updates

    The update addresses six .NET Framework vulnerabilities. Some WPF printing problems are resolved only by later cumulative updates.

    Check the newer update, KB5126048

    Key changes 6 CVEs · 6 changes

    • Fix .NET Framework: An elevation-of-privilege vulnerability in .NET Framework is addressed.
    • Fix .NET Framework: An elevation-of-privilege vulnerability in .NET Framework is addressed.
    • Fix .NET Framework: A remote code execution vulnerability in .NET Framework is addressed.

    Read update Source: Microsoft

    Builds
    4.8.4805.0 · 2.0.50727.9070
    Security
    6 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.7.2 .NET Framework 3.5 / 4.7.2 for Windows 10 1809 · Windows Server 2019 Security update

    KB5120698

    Six .NET vulnerabilities addressed; WPF issues resolved later

    The update addresses six .NET Framework vulnerabilities. Two WPF printing issues were later resolved in the September and October 2026 cumulative updates.

    Check the newer update, KB5126043

    Key changes 6 CVEs · 6 changes

    • Improved .NET Framework: The update addresses a .NET Framework elevation-of-privilege vulnerability.
    • Improved .NET Framework: The update addresses a .NET Framework elevation-of-privilege vulnerability.
    • Improved .NET Framework: The update addresses a .NET Framework remote-code-execution vulnerability.

    Read update Source: Microsoft

    Builds
    4.7.4144.0 · 2.0.50727.9070
    Security
    6 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 26H1 Security update

    KB5101002

    Fixes hanging HTTP requests and debugger value reports

    Addresses 17 .NET Framework security vulnerabilities and fixes two reliability issues, including HTTP requests that could hang in certain secure connection scenarios.

    Check the newer update, KB5120711

    Key changes 17 CVEs · 2 changes

    • Fix .NET Libraries: Some synchronous web requests no longer hang in the specified secure connection scenarios.
    • Fix .NET Runtime: The Visual Studio x86 debugger reports certain floating-point values correctly while stepping through mixed-code applications.
    • CVSS 8.1 CVE-2026-47304: .NET Security Feature Bypass Vulnerability

    Read update Source: Microsoft

    Build
    4.8.9340.0
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 25H2 · Windows Server 2025 Security update

    KB5100998

    Remote-code execution flaw among 17 vulnerabilities addressed

    Addresses 17 Important .NET vulnerabilities, including a remote-code execution flaw, and two reliability issues. None are rated Critical or known to be publicly disclosed or exploited.

    Check the newer update, KB5120708

    Key changes 17 CVEs · 19 changes

    • Fix .NET Framework: The update addresses a security flaw that could cause denial of service.
    • Fix .NET Framework: The update addresses a security feature bypass flaw.
    • Fix .NET Framework: The update addresses a security flaw that could cause denial of service.

    Read update Source: Microsoft

    Builds
    4.8.9340.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 24H2 Security update

    KB5101001

    Runtime flaws addressed; secure requests and debugging improved

    The update addresses 17 important vulnerabilities. It also addresses hangs in some secure web requests and wrong values in Visual Studio debugging.

    Check the newer update, KB5120710

    Key changes 17 CVEs · 19 changes

    • Fix .NET Framework: A flaw could let someone disrupt a service.
    • Fix .NET Framework: A flaw could let someone get around a security feature.
    • Fix .NET Framework: A flaw could let someone disrupt a service.

    Read update Source: Microsoft

    Builds
    4.8.9339.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 23H2 Security update

    KB5101004

    Remote code execution flaw addressed; secure request hangs improved

    The update addresses 17 Important vulnerabilities, including a remote code execution flaw, and two reliability issues involving hanging secure web requests and incorrect debugger reports.

    Check the newer update, KB5120713

    Key changes 17 CVEs · 2 changes

    • Fix .NET Libraries: The update addresses cases where secure web requests could hang with certain server configurations.
    • Fix .NET Runtime: The update addresses cases where certain floating-point values could be reported incorrectly while debugging.
    • CVSS 8.1 CVE-2026-47304: .NET Security Feature Bypass Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9339.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Security update

    KB5101000

    17 .NET flaws addressed; secure web requests and debugger improved

    The update addresses 17 important .NET Framework security flaws, including one that could let an attacker run code. It also addresses hanging secure web requests and incorrect debugger values.

    Check the newer update, KB5120709

    Key changes 17 CVEs · 19 changes

    • Fix .NET Framework: A flaw that could disrupt a service is addressed.
    • Fix .NET Framework: A flaw that could bypass a security check is addressed.
    • Fix .NET Framework: A flaw that could disrupt a service is addressed.

    Read update Source: Microsoft

    Builds
    4.8.9339.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Security update

    KB5101005

    Secure web requests and debugger value reports improved

    Addresses 17 .NET Framework vulnerabilities and two reliability issues. Some secure web requests could hang, and a debugger could report certain values incorrectly.

    Check the newer update, KB5120714

    Key changes 17 CVEs · 19 changes

    • Fix .NET Framework: Addresses a flaw that could make an app stop responding.
    • Fix .NET Framework: Addresses a flaw that could let an attacker get around a security check.
    • Fix .NET Framework: Addresses a flaw that could make an app stop responding.

    Read update Source: Microsoft

    Builds
    4.8.9339.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Security update

    KB5101006

    Remote code execution flaw addressed; stalled requests targeted

    The update addresses 17 .NET Framework vulnerabilities, including a remote code execution flaw, and addresses cases where synchronous secure HTTP requests could hang. All 17 are rated Important; none are Critical.

    Check the newer update, KB5120701

    Key changes 17 CVEs · 18 changes

    • Fix .NET Framework: A .NET Framework denial of service vulnerability is addressed (CVE-2026-47302).
    • Fix .NET Framework: A .NET Framework security feature bypass vulnerability is addressed (CVE-2026-47304).
    • Fix .NET Framework: A .NET Framework denial of service vulnerability is addressed (CVE-2026-50304).

    Read update Source: Microsoft

    Builds
    4.8.4803.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Security update

    KB5101010

    Remote-code-execution flaw addressed; web-request hangs targeted

    Addresses 17 Important .NET Framework vulnerabilities, including a remote-code-execution flaw, and addresses an issue that could make some synchronous web requests hang.

    Check the newer update, KB5120705

    Key changes 17 CVEs · 1 change

    • Fix .NET Libraries: The update addresses an issue that could make some synchronous web requests hang during secure connections.
    • CVSS 8.1 CVE-2026-47304: .NET Security Feature Bypass Vulnerability
    • CVSS 7.8 CVE-2026-50646: .NET Framework Remote Code Execution Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.4803.0 · 2.0.50727.9182
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Security update

    KB5101008

    Remote code execution flaw addressed; secure requests improved

    The update addresses 17 Important .NET Framework vulnerabilities, including a remote code execution flaw, and addresses hangs in some synchronous web requests.

    Check the newer update, KB5120703

    Key changes 17 CVEs · 1 change

    • Fix .NET Libraries: The update addresses hangs in synchronous web requests during certain secure connections with specific server configurations.
    • CVSS 8.1 CVE-2026-47304: .NET Security Feature Bypass Vulnerability
    • CVSS 7.8 CVE-2026-50646: .NET Framework Remote Code Execution Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.4803.0 · 2.0.50727.9069
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.7.2 .NET Framework 3.5 / 4.7.2 for Windows 10 1809 · Windows Server 2019 Security update

    KB5100989

    Secure web request hangs addressed; 17 security flaws fixed

    Fixes 17 Important .NET Framework security flaws and a problem that could leave some secure web requests stuck. A restart may be needed if affected files are in use.

    Check the newer update, KB5120698

    Key changes 17 CVEs · 18 changes

    • Fix .NET Framework: A flaw that could make a .NET app stop responding is fixed.
    • Fix .NET Framework: A flaw that could bypass a security feature is fixed.
    • Fix .NET Framework: A flaw that could make a .NET app stop responding is fixed.

    Read update Source: Microsoft

    Builds
    4.7.4143.0 · 2.0.50727.9069
    Security
    17 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 26H1 Optional preview
    Preview

    KB5092431

    HttpWebRequest hangs and x86 debugger values corrected

    Addresses cases where secure web requests hang and where Visual Studio's x86 debugger reports some floating-point values incorrectly.

    Check the newer update, KB5101002

    Key changes 2 changes

    • Fix .NET Libraries: The update addresses cases where secure web requests could hang with certain server configurations.
    • Fix .NET Runtime: The update addresses cases where some floating-point values could be reported incorrectly while stepping through mixed-code application...

    Read update Source: Microsoft

    Build
    4.8.9337.0
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 25H2 Optional preview
    Preview

    KB5092427

    Hanging secure requests and incorrect debugger values addressed

    Addresses hanging synchronous web requests in certain secure-connection setups and incorrect floating-point values in Visual Studio’s x86 native debugger.

    Check the newer update, KB5100998

    Key changes 2 changes

    • Fix .NET Libraries: Synchronous web requests are less likely to hang in certain secure-connection setups.
    • Fix .NET Runtime: Some floating-point values are reported more accurately when stepping through mixed-code applications in the Visual Studio x86 native d...

    Read update Source: Microsoft

    Builds
    4.8.9337.0 · 2.0.50727.9181
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 24H2 Optional preview
    Preview

    KB5092430

    Hanging secure requests and debugger values addressed

    Addresses cases where secure HTTP requests could hang and floating-point values could be reported incorrectly in Visual Studio’s x86 native debugger.

    Check the newer update, KB5101001

    Key changes 2 changes

    • Fix .NET Libraries: Some requests over secure connections could hang with certain server setups; this update addresses the issue.
    • Fix .NET Runtime: Floating-point values could be reported incorrectly while stepping through code in Visual Studio’s x86 native debugger; this update add...

    Read update Source: Microsoft

    Builds
    4.8.9336.0 · 2.0.50727.9181
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 26H1 Security update

    KB5087055

    Two framework flaws could allow higher access

    Addresses two .NET Framework flaws that could let someone gain higher access: CVE-2026-32177 and CVE-2026-35433.

    Check the newer update, KB5101002

    Key changes 2 CVEs · 2 changes

    • Fix .NET Framework: A flaw could let someone gain higher access.
    • Fix .NET Framework: A flaw could let someone gain higher access.
    • CVSS 7.3 CVE-2026-32177: .NET Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Build
    4.8.9335.0
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 25H2 · Windows Server 2025 Security update

    KB5087051

    Two framework flaws could let someone gain higher access

    The update fixes two .NET Framework flaws that could let someone gain higher access. It installs through Windows Update and needs a restart if affected files are in use.

    Check the newer update, KB5100998

    Key changes 2 CVEs · 2 changes

    • Fix .NET Framework: A flaw that could let someone gain higher access is addressed.
    • Fix .NET Framework: A flaw that could let someone gain higher access is addressed.
    • CVSS 7.3 CVE-2026-32177: .NET Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9335.0 · 2.0.50727.9181
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 24H2 Security update

    KB5087054

    Two .NET privilege flaws addressed

    Addresses two Important .NET Framework security flaws. Both could let someone gain higher access than intended.

    Check the newer update, KB5101001

    Key changes 2 CVEs · 2 changes

    • Improved .NET Framework: A security flaw could let someone gain higher access than intended.
    • Improved .NET Framework: A security flaw could let someone gain higher access than intended.
    • CVSS 7.3 CVE-2026-32177: .NET Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9334.0 · 2.0.50727.9181
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 23H2 Security update

    KB5087058

    Runtime elevation-of-privilege flaws addressed

    Two .NET Framework elevation-of-privilege vulnerabilities, CVE-2026-32177 and CVE-2026-35433, are addressed. A restart is required if affected files are in use.

    Check the newer update, KB5101004

    Key changes 2 CVEs · 2 changes

    • Fix .NET Framework: An elevation-of-privilege security vulnerability tracked as CVE-2026-32177 is addressed.
    • Fix .NET Framework: An elevation-of-privilege security vulnerability tracked as CVE-2026-35433 is addressed.
    • CVSS 7.3 CVE-2026-32177: .NET Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9334.0 · 2.0.50727.9181
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Security update

    KB5087053

    Two .NET runtime elevation-of-privilege flaws addressed

    The update addresses two elevation-of-privilege vulnerabilities in .NET Framework 3.5 and 4.8.1. A restart might be required if affected files are in use.

    Check the newer update, KB5101000

    Key changes 2 CVEs · 2 changes

    • Fix .NET Framework: The update addresses an elevation-of-privilege vulnerability in .NET Framework.
    • Fix .NET Framework: The update addresses an elevation-of-privilege vulnerability in .NET Framework.
    • CVSS 7.3 CVE-2026-32177: .NET Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9334.0 · 2.0.50727.9181
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Security update

    KB5087059

    Two flaws could give attackers more access

    Addresses two important security flaws in .NET Framework. It applies to Windows Server 2022 devices with .NET Framework 3.5 or 4.8.1 installed.

    Check the newer update, KB5101005

    Key changes 2 CVEs · 2 changes

    • Improved .NET Framework: Addresses a security flaw that could let an attacker gain more access.
    • Improved .NET Framework: Addresses a security flaw that could let an attacker gain more access.
    • CVSS 7.3 CVE-2026-32177: .NET Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9334.0 · 2.0.50727.9181
    Security
    2 vulnerabilities fixed
    Restart
    Required