Document August 2026 WPF known issue

[rbhanda]

Summary

• document the August 2026 WPF printing and PDF/XPS known issue for .NET 8, 9, and 10
• provide the temporary runtimeconfig.json AppContext switch workaround
• warn that the workaround disables protections introduced in the August 2026 update

Validation

• markdownlint passes for each newly added section
• markdown link checks pass for all three changed files
• diff whitespace check passes with the existing CRLF format in the .NET 10 file

[ToreDemant]

Are there a similar entry for .Net Framework that has same issue after the August update?

[TaraOverfield]

Are there a similar entry for .Net Framework that has same issue after the August update?

Yes, .NET and .NET Framework are both impacted by the same issue. We're both publishing known issues with nearly the same message. The only difference is the opt out mechanism which applies specifically to the product being used.

[ToreDemant]

Are there a similar entry for .Net Framework that has same issue after the August update?

Yes, .NET and .NET Framework are both impacted by the same issue. We're both publishing known issues with nearly the same message. The only difference is the opt out mechanism which applies specifically to the product being used.

Found it:
https://learn.microsoft.com/en-us/dotnet/framework/release-notes/2026/08-11-august-cumulative-update