diff --git a/ICSharpCode.ILSpyX/Metadata/PdbDumper.cs b/ICSharpCode.ILSpyX/Metadata/PdbDumper.cs
index e0a94a8b40..9a7b675fb4 100644
--- a/ICSharpCode.ILSpyX/Metadata/PdbDumper.cs
+++ b/ICSharpCode.ILSpyX/Metadata/PdbDumper.cs
@@ -20,6 +20,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
+using System.Reflection.PortableExecutable;
 using System.Linq;
 using System.Text;
 using System.Text.Json;
@@ -116,6 +117,13 @@ internal static ReaderParameters CreateReaderParameters(string? pdbFileName)
 
 		static ModuleDefinition ReadModuleWithSymbols(string assemblyFileName, string? pdbFileName)
 		{
+			using (var stream = File.OpenRead(assemblyFileName))
+			using (var reader = new PEReader(stream))
+			{
+				if (reader.ReadDebugDirectory().Any(e => e.Type == DebugDirectoryEntryType.EmbeddedPortablePdb
+					&& DebugInfoUtils.IsEmbeddedPortablePdbTooLarge(reader, e)))
+					throw new NoDebugSymbolsException($"Embedded Portable PDB is too large for '{assemblyFileName}'.");
+			}
 			var parameters = CreateReaderParameters(pdbFileName);
 			ModuleDefinition module;
 			try
@@ -137,6 +145,14 @@ static ModuleDefinition ReadModuleWithSymbols(string assemblyFileName, string? p
 
 		static ModuleDefinition ReadModuleWithSymbols(Stream assemblyStream, string assemblyName, string? pdbFileName)
 		{
+			long position = assemblyStream.Position;
+			using (var reader = new PEReader(assemblyStream, PEStreamOptions.LeaveOpen))
+			{
+				if (reader.ReadDebugDirectory().Any(e => e.Type == DebugDirectoryEntryType.EmbeddedPortablePdb
+					&& DebugInfoUtils.IsEmbeddedPortablePdbTooLarge(reader, e)))
+					throw new NoDebugSymbolsException($"Embedded Portable PDB is too large for '{assemblyName}'.");
+			}
+			assemblyStream.Position = position;
 			var parameters = new ReaderParameters { ReadSymbols = true, InMemory = true };
 			ApplyExplicitSymbolFile(parameters, pdbFileName);
 			ModuleDefinition module;
diff --git a/ICSharpCode.ILSpyX/PdbProvider/DebugInfoUtils.cs b/ICSharpCode.ILSpyX/PdbProvider/DebugInfoUtils.cs
index 5605a941b8..a125343dbf 100644
--- a/ICSharpCode.ILSpyX/PdbProvider/DebugInfoUtils.cs
+++ b/ICSharpCode.ILSpyX/PdbProvider/DebugInfoUtils.cs
@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Buffers.Binary;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Reflection.Metadata;
@@ -32,6 +33,23 @@ namespace ICSharpCode.ILSpyX.PdbProvider
 {
 	public static class DebugInfoUtils
 	{
+		internal const int MaxEmbeddedPortablePdbSize = 128 * 1024 * 1024;
+
+		public static bool IsEmbeddedPortablePdbTooLarge(PEReader reader, DebugDirectoryEntry entry)
+		{
+			if (entry.DataSize < 8)
+				return false;
+			try
+			{
+				int offset = reader.IsLoadedImage ? entry.DataRelativeVirtualAddress : entry.DataPointer;
+				var data = reader.GetEntireImage().GetContent(offset, 8);
+				return BinaryPrimitives.ReadUInt32LittleEndian(data.AsSpan().Slice(4, 4)) > MaxEmbeddedPortablePdbSize;
+			}
+			catch (ArgumentOutOfRangeException)
+			{
+				return false;
+			}
+		}
 		public static IDebugInfoProvider? LoadSymbols(PEFile module)
 		{
 			try
@@ -131,6 +149,9 @@ static bool TryOpenPortablePdb(PEFile module,
 			{
 				if (entry.IsPortableCodeView)
 				{
+					if (entry.Type == DebugDirectoryEntryType.EmbeddedPortablePdb
+						&& IsEmbeddedPortablePdbTooLarge(reader, entry))
+						return false;
 					return reader.TryOpenAssociatedPortablePdb(module.FileName, OpenStream,
 						out provider, out pdbFileName);
 				}
diff --git a/ILSpy/Metadata/DebugDirectoryTreeNode.cs b/ILSpy/Metadata/DebugDirectoryTreeNode.cs
index 3e802b3303..396b511794 100644
--- a/ILSpy/Metadata/DebugDirectoryTreeNode.cs
+++ b/ILSpy/Metadata/DebugDirectoryTreeNode.cs
@@ -22,6 +22,7 @@
 using System.Reflection.PortableExecutable;
 
 using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.ILSpyX.PdbProvider;
 
 using ICSharpCode.ILSpy.TreeNodes;
 using ICSharpCode.ILSpy.ViewModels;
@@ -104,6 +105,8 @@ protected override void LoadChildren()
 					case DebugDirectoryEntryType.EmbeddedPortablePdb:
 						try
 						{
+							if (DebugInfoUtils.IsEmbeddedPortablePdbTooLarge(module.Reader, entry))
+								break;
 							var provider = module.Reader.ReadEmbeddedPortablePdbDebugDirectoryData(entry);
 							var pdbMetadata = new MetadataFile(
 								MetadataFile.MetadataFileKind.ProgramDebugDatabase,