Merge main into live

.openpublishing.redirection.csharp.json

@@ -803,6 +803,14 @@
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8176.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
         },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8177.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/async-await-errors"
+        },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8178.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/async-await-errors"
+        },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8373.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/ref-modifiers-errors"
@@ -819,10 +827,18 @@
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8401.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/feature-version-errors"
         },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8403.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/async-await-errors"
+        },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8410.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/using-statement-declaration-errors#implementing-idisposable-and-iasyncdisposable"
         },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8411.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/async-await-errors"
+        },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8417.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/using-statement-declaration-errors#implementing-idisposable-and-iasyncdisposable"
@@ -2925,6 +2941,14 @@
             "source_path_from_root": "/docs/csharp/misc/cs3016.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/array-declaration-errors"
         },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs8506.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/pattern-matching-warnings"
+        },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8515.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/pattern-matching-warnings"
+        },
         {
             "source_path_from_root": "/docs/csharp/namespaces-and-assemblies.md",
             "redirect_url": "/dotnet/csharp/fundamentals/types/namespaces"

docs/core/diagnostics/symbols.md

@@ -1,7 +1,8 @@
 ---
 title: Symbols in .NET
 description: An introduction to symbols and portable PDBs in .NET
-ms.date: 02/08/2021
+ms.date: 03/12/2026
+ai-usage: ai-assisted
 ---
 
 # Symbols
@@ -20,6 +21,9 @@ A PDB file is an auxiliary file produced by a compiler to provide other tools, e
 
 The Portable PDB format was introduced in .NET Core, and it's used by default when targeting .NET. When targeting .NET Framework, you can enable portable PDB symbols by specifying `<DebugType>portable</DebugType>` in your project file. The portable PDB format is based on ECMA-335 metadata format. For more information, see [Portable PDB v1.0: Format Specification](https://github.com/dotnet/runtime/blob/main/docs/design/specs/PortablePdb-Metadata.md). Diagnostic tools can use the <xref:System.Reflection.Metadata> library to read portable PDB files (for an example, see <xref:System.Reflection.Metadata.Document?displayProperty=nameWithType>).
 
+> [!CAUTION]
+> The <xref:System.Reflection.Metadata> library is not designed to handle untrusted input. Malformed or malicious PDB files can cause unexpected behavior, including out-of-bounds memory access, crashes, or hangs. Only use this API with trusted files.
+
 ## Use the correct PDB format for your scenario
 
 Neither portable PDBs nor Windows PDBs are supported everywhere. To decide which format to use, consider where your project will be used and debugged. If you have a project that you want to be able to use and debug in both formats, you can use different build configurations and build the project twice to support both types of consumer.