SDK 1.0.3796-prerelease, for Runtime 145 (Jan. 19, 2026)

Release notes for Microsoft Edge WebView2 Prerelease SDK, release date: Jan. 19, 2026.

NuGet package for WebView2 SDK 1.0.3796-prerelease

For full API compatibility, this Prerelease version of the WebView2 SDK requires the WebView2 Runtime that ships with Microsoft Edge version 145.0.3796.0 or later; see Runtime 145.0.3800.47 (Feb. 16, 2026).

Detailed contents:

• Experimental APIs (Phase 1: Experimental in Prerelease)
  • Enhanced Security Mode Level
• Bug fixes
• See also

Experimental APIs (Phase 1: Experimental in Prerelease)

The following APIs are in Phase 1: Experimental in Prerelease, and have been added in this Prerelease SDK.

Enhanced Security Mode Level

The Enhanced Security Mode Level API enables configuring Enhanced Security Mode (ESM) for WebView2 instances. ESM reduces the risk of memory-related vulnerabilities by disabling JavaScript Just-in-Time (JIT) compilation and enabling additional operating system protections.

To control the ESM level for all WebView2 instances that share the same profile, use the EnhancedSecurityModeLevel property on CoreWebView2Profile (or ICoreWebView2ExperimentalProfile9):

• Use the Off value to completely disable Enhanced Security Mode (default behavior).

• Use the Strict value to enable enhanced security for all sites. This disables JIT compilation and applies additional OS-level protections, improving security but potentially reducing JavaScript performance.

.NET/C#

• CoreWebView2EnhancedSecurityModeLevel Enum

  • CoreWebView2EnhancedSecurityModeLevel.Off
  • CoreWebView2EnhancedSecurityModeLevel.Strict

• CoreWebView2Profile Class:

  • CoreWebView2Profile.EnhancedSecurityModeLevel Property

WinRT/C#

• CoreWebView2EnhancedSecurityModeLevel Enum

  • CoreWebView2EnhancedSecurityModeLevel.Off
  • CoreWebView2EnhancedSecurityModeLevel.Strict

• CoreWebView2Profile Class:

  • CoreWebView2Profile.EnhancedSecurityModeLevel Property

Win32/C++

• ICoreWebView2ExperimentalProfile9

  • ICoreWebView2ExperimentalProfile9::get_EnhancedSecurityModeLevel
  • ICoreWebView2ExperimentalProfile9::put_EnhancedSecurityModeLevel

• COREWEBVIEW2_ENHANCED_SECURITY_MODE_LEVEL enum

  • COREWEBVIEW2_ENHANCED_SECURITY_MODE_LEVEL_OFF
  • COREWEBVIEW2_ENHANCED_SECURITY_MODE_LEVEL_STRICT

Bug fixes

• Added the article Performance best practices for WebView2 apps, about how to improve the startup speed, memory usage, and responsiveness of a WebView2 app.

See also

• Runtime 145.0.3800.47 (Feb. 16, 2026)
• Release notes for WebView2
  • Release notes for the WebView2 Runtime
  • Release notes for WebView2 SDKs