diff --git a/OpenNest.FrontEnd.Tests/RegexImportFailureTests.cs b/OpenNest.FrontEnd.Tests/RegexImportFailureTests.cs
new file mode 100644
index 0000000..38c4405
--- /dev/null
+++ b/OpenNest.FrontEnd.Tests/RegexImportFailureTests.cs
@@ -0,0 +1,191 @@
+using System.Reflection;
+using System.Security.Cryptography;
+using System.Text.RegularExpressions;
+using ACadSharp;
+using ACadSharp.IO;
+using CSMath;
+using OpenNest.Api;
+using OpenNest.Bending;
+using OpenNest.Engine.Jobs;
+using OpenNest.Geometry;
+using OpenNest.IO.Bending;
+using OpenNest.Mcp;
+using OpenNest.Mcp.Tools;
+using CadLayer = ACadSharp.Tables.Layer;
+using CadLine = ACadSharp.Entities.Line;
+
+namespace OpenNest.FrontEnd.Tests;
+
+// Console redirection and both registries are process-static. Reuse the existing
+// nonparallel front-end collection; these tests require a Windows runtime.
+[Collection("FrontEndRegistry")]
+public class RegexImportFailureTests : IDisposable
+{
+    private const string MarkerLayer = "TESTTIMEOUT";
+    private readonly string directory = Path.Combine(Path.GetTempPath(), "opennest-regex-frontends-" + Guid.NewGuid());
+    private readonly MarkerDetector detector = new();
+
+    public RegexImportFailureTests()
+    {
+        Directory.CreateDirectory(directory);
+        BendDetectorRegistry.Register(detector);
+    }
+
+    public void Dispose()
+    {
+        // No unregister API: retained registrations become inert, and active
+        // registrations only throw for the marker document, never ordinary imports.
+        detector.Active = false;
+        Directory.Delete(directory, true);
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void Console_TimeoutExitsOneWithoutOutputEvenAfterEarlierImport(bool earlierSuccess)
+    {
+        var bad = WriteDxf("marker.dxf", marker: true);
+        var hash = Hash(bad);
+        var output = Path.Combine(directory, "output.nest");
+        var args = new List<string>();
+        if (earlierSuccess)
+            args.Add(WriteDxf("good.dxf", marker: false));
+        args.AddRange(new[] { bad, "--size", "20x30", "--output", output,
+            "--repair-bends-mm", "2", "--cad-units", "inches" });
+        var originalOut = System.Console.Out;
+        var originalError = System.Console.Error;
+        using var stdout = new StringWriter();
+        using var stderr = new StringWriter();
+        try
+        {
+            System.Console.SetOut(stdout);
+            System.Console.SetError(stderr);
+            Assert.Equal(1, RunConsole(args.ToArray()));
+        }
+        finally
+        {
+            System.Console.SetOut(originalOut);
+            System.Console.SetError(originalError);
+        }
+
+        Assert.Equal(1, detector.CallCount);
+        Assert.Contains("Error: failed to import DXF", stderr.ToString());
+        Assert.Contains(bad, stderr.ToString());
+        if (earlierSuccess)
+            Assert.Contains("Imported: good", stdout.ToString());
+        Assert.DoesNotContain("Bend repair", stdout.ToString());
+        Assert.False(File.Exists(output));
+        Assert.Equal(hash, Hash(bad));
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public async Task Api_TimeoutRetainsInnerExceptionAndNeverSolvesOrReturnsResponse(bool earlierSuccess)
+    {
+        var bad = WriteDxf("marker.dxf", marker: true);
+        var hash = Hash(bad);
+        var engine = new CountingEngine();
+        var engineName = "RegexImportFailure-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engineName, "test", () => engine);
+        var parts = new List<NestRequestPart>();
+        if (earlierSuccess)
+            parts.Add(new NestRequestPart { Id = "good", DxfPath = WriteDxf("good.dxf", marker: false), Quantity = 1 });
+        parts.Add(new NestRequestPart { Id = "bad", DxfPath = bad, Quantity = 1 });
+        var request = new NestRequest
+        {
+            Parts = parts,
+            Plates = [new NestRequestPlate { Id = "stock", Size = new Size(20, 30), Quantity = 1 }],
+            Engine = engineName,
+        };
+        NestResponse? response = null;
+
+        var exception = await Assert.ThrowsAsync<InvalidOperationException>(async () =>
+            response = await NestRunner.RunAsync(request));
+
+        Assert.IsType<RegexMatchTimeoutException>(exception.InnerException);
+        Assert.Same(detector.Timeout, exception.InnerException);
+        Assert.Contains(bad, exception.Message);
+        Assert.Equal(1, detector.CallCount);
+        Assert.Equal(0, engine.CallCount);
+        Assert.Null(response);
+        Assert.Equal(hash, Hash(bad));
+    }
+
+    [Fact]
+    public void Mcp_TimeoutReturnsErrorWithoutAddingDrawingOrChangingEarlierDrawing()
+    {
+        var good = WriteDxf("good.dxf", marker: false);
+        var bad = WriteDxf("marker.dxf", marker: true);
+        var hash = Hash(bad);
+        var session = new NestSession();
+        var tools = new InputTools(session);
+        Assert.StartsWith("Imported drawing", tools.ImportDxf(good));
+        var earlier = Assert.Single(session.Drawings);
+        var earlierProgram = earlier.Program;
+        var count = session.Drawings.Count;
+
+        var result = tools.ImportDxf(bad);
+
+        Assert.StartsWith("Error:", result);
+        Assert.Contains(bad, result);
+        Assert.Equal(count, session.Drawings.Count);
+        Assert.Same(earlier, Assert.Single(session.Drawings));
+        Assert.Same(earlierProgram, earlier.Program);
+        Assert.Equal(1, detector.CallCount);
+        Assert.Equal(hash, Hash(bad));
+    }
+
+    private static int RunConsole(params string[] args)
+    {
+        var method = Assembly.Load("OpenNest.Console").GetType("NestConsole")!
+            .GetMethod("Run", BindingFlags.Static | BindingFlags.Public)!;
+        return (int)method.Invoke(null, new object[] { args })!;
+    }
+
+    private string WriteDxf(string name, bool marker)
+    {
+        var document = new CadDocument();
+        document.Header.InsUnits = ACadSharp.Types.Units.UnitsType.Inches;
+        document.Entities.Add(new CadLine(new XYZ(0, 0, 0), new XYZ(2, 0, 0))
+        {
+            Layer = new CadLayer(marker ? MarkerLayer : "0"),
+        });
+        document.Entities.Add(new CadLine(new XYZ(2, 0, 0), new XYZ(2, 2, 0)));
+        document.Entities.Add(new CadLine(new XYZ(2, 2, 0), new XYZ(0, 2, 0)));
+        document.Entities.Add(new CadLine(new XYZ(0, 2, 0), new XYZ(0, 0, 0)));
+        var path = Path.Combine(directory, name);
+        DxfWriter.Write(path, document, false);
+        return path;
+    }
+
+    private static byte[] Hash(string path) => SHA256.HashData(File.ReadAllBytes(path));
+
+    private sealed class MarkerDetector : IBendDetector
+    {
+        public string Name { get; } = "FrontEndRegexTimeout-" + Guid.NewGuid();
+        public bool Active { get; set; } = true;
+        public int CallCount { get; private set; }
+        public RegexMatchTimeoutException Timeout { get; } = new("marker", "<test>", TimeSpan.FromSeconds(1));
+
+        public List<Bend> DetectBends(CadDocument document)
+        {
+            if (!Active || !document.Entities.Any(e => e.Layer?.Name == MarkerLayer))
+                return new List<Bend>();
+            CallCount++;
+            throw Timeout;
+        }
+    }
+
+    private sealed class CountingEngine : INestingEngine
+    {
+        public int CallCount { get; private set; }
+
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            CallCount++;
+            throw new InvalidOperationException("Import failure must abort before solving.");
+        }
+    }
+}
diff --git a/OpenNest.IO/Bending/SolidWorksBendDetector.cs b/OpenNest.IO/Bending/SolidWorksBendDetector.cs
index 3d66963..588eff1 100644
--- a/OpenNest.IO/Bending/SolidWorksBendDetector.cs
+++ b/OpenNest.IO/Bending/SolidWorksBendDetector.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
@@ -17,17 +18,26 @@ namespace OpenNest.IO.Bending
 
         private static readonly Regex BendNoteRegex = new Regex(
             @"(?<direction>UP|DOWN|DN)\s+(?<angle>\d+(\.\d+)?)[^A-Z\d]*R\s*(?<radius>\d+(\.\d+)?)",
-            RegexOptions.Compiled | RegexOptions.IgnoreCase
+            RegexOptions.Compiled | RegexOptions.IgnoreCase,
+            TimeSpan.FromSeconds(1)
         );
 
         private static readonly Regex MTextFormatRegex = new Regex(
             @"\\[fHCTQWASpOoLlKk][^;]*;|\\P|[{}]|%%[dDpPcC]",
-            RegexOptions.Compiled
+            RegexOptions.Compiled,
+            TimeSpan.FromSeconds(1)
         );
 
         private static readonly Regex UnicodeEscapeRegex = new Regex(
             @"\\U\+([0-9A-Fa-f]{4})",
-            RegexOptions.Compiled
+            RegexOptions.Compiled,
+            TimeSpan.FromSeconds(1)
+        );
+
+        private static readonly Regex WhitespaceRegex = new Regex(
+            @"\s+",
+            RegexOptions.None,
+            TimeSpan.FromSeconds(1)
         );
 
         public List<Bend> DetectBends(CadDocument document)
@@ -238,7 +248,7 @@ namespace OpenNest.IO.Bending
             result = MTextFormatRegex.Replace(result, " ");
 
             // Collapse multiple spaces
-            return Regex.Replace(result.Trim(), @"\s+", " ");
+            return WhitespaceRegex.Replace(result.Trim(), " ");
         }
 
         private MText FindClosestBendNote(ACadSharp.Entities.Line bendLine, List<MText> notes)
diff --git a/OpenNest.Tests/Bending/SolidWorksBendDetectorTests.cs b/OpenNest.Tests/Bending/SolidWorksBendDetectorTests.cs
index f2873ed..df16541 100644
--- a/OpenNest.Tests/Bending/SolidWorksBendDetectorTests.cs
+++ b/OpenNest.Tests/Bending/SolidWorksBendDetectorTests.cs
@@ -1,3 +1,5 @@
+using System.Reflection;
+using System.Text.RegularExpressions;
 using ACadSharp.IO;
 using OpenNest.Bending;
 using OpenNest.IO.Bending;
@@ -6,6 +8,50 @@ namespace OpenNest.Tests.Bending;
 
 public class SolidWorksBendDetectorTests
 {
+    [Theory]
+    [InlineData("BendNoteRegex")]
+    [InlineData("MTextFormatRegex")]
+    [InlineData("UnicodeEscapeRegex")]
+    [InlineData("WhitespaceRegex")]
+    public void DetectorRegex_HasExplicitTimeout(string fieldName)
+    {
+        var field = typeof(SolidWorksBendDetector).GetField(fieldName,
+            BindingFlags.Static | BindingFlags.NonPublic);
+        Assert.NotNull(field);
+        var regex = Assert.IsType<Regex>(field.GetValue(null));
+        Assert.Equal(TimeSpan.FromSeconds(1), regex.MatchTimeout);
+    }
+
+    [Theory]
+    [InlineData("UP 90 R0.125", BendDirection.Up, 0.125, "UP 90 R0.125")]
+    [InlineData("DOWN 90 R0.313", BendDirection.Down, 0.313, "DOWN 90 R0.313")]
+    [InlineData("DN 90 SHARP", BendDirection.Down, 0.0, "DN 90 SHARP")]
+    [InlineData(@"{\fArial;UP\P90\U+00B0 R0.125}", BendDirection.Up, 0.125, "UP 90° R0.125")]
+    [InlineData("UP\t90%%d   R0.125", BendDirection.Up, 0.125, "UP 90° R0.125")]
+    [InlineData(@"UP 90 R0.125 \fUnterminated", BendDirection.Up, 0.125, @"UP 90 R0.125 \fUnterminated")]
+    public void DetectBends_PreservesDirectionFormattingAndRadius(string text,
+        BendDirection direction, double radius, string expectedNote)
+    {
+        var document = new ACadSharp.CadDocument();
+        document.Entities.Add(new ACadSharp.Entities.Line(new CSMath.XYZ(0, 0, 0), new CSMath.XYZ(10, 0, 0))
+        {
+            Layer = new ACadSharp.Tables.Layer("BEND"),
+            LineType = new ACadSharp.Tables.LineType("CENTER"),
+        });
+        document.Entities.Add(new ACadSharp.Entities.MText
+        {
+            Value = text,
+            InsertPoint = new CSMath.XYZ(5, 0, 0),
+            Height = 1,
+        });
+
+        var bend = Assert.Single(new SolidWorksBendDetector().DetectBends(document));
+        Assert.Equal(direction, bend.Direction);
+        Assert.Equal(90.0, bend.Angle);
+        Assert.Equal(radius, bend.Radius);
+        Assert.Equal(expectedNote, bend.NoteText);
+    }
+
     [Fact]
     public void SolidWorksDetector_IsRegistered()
     {
diff --git a/OpenNest.Tests/IO/CadImporterTimeoutTests.cs b/OpenNest.Tests/IO/CadImporterTimeoutTests.cs
new file mode 100644
index 0000000..af6da32
--- /dev/null
+++ b/OpenNest.Tests/IO/CadImporterTimeoutTests.cs
@@ -0,0 +1,173 @@
+using System.Security.Cryptography;
+using System.Text.RegularExpressions;
+using ACadSharp;
+using ACadSharp.IO;
+using CSMath;
+using OpenNest.Bending;
+using OpenNest.IO;
+using OpenNest.IO.Bending;
+using CadLayer = ACadSharp.Tables.Layer;
+using CadLine = ACadSharp.Entities.Line;
+
+namespace OpenNest.Tests.IO;
+
+[CollectionDefinition("Bend detector timeout registry", DisableParallelization = true)]
+public class BendDetectorTimeoutRegistryCollection { }
+
+[Collection("Bend detector timeout registry")]
+public class CadImporterTimeoutTests : IDisposable
+{
+    private const string MarkerLayer = "TESTTIMEOUT";
+    private readonly string directory = Path.Combine(Path.GetTempPath(), "opennest-regex-" + Guid.NewGuid());
+    private readonly List<MarkerDetector> registered = new();
+
+    public CadImporterTimeoutTests() => Directory.CreateDirectory(directory);
+
+    public void Dispose()
+    {
+        // Register has no unregister API. Disable every double after its test, and
+        // gate calls on the marker layer while active. Never mutate the private registry.
+        foreach (var detector in registered)
+            detector.Active = false;
+        Directory.Delete(directory, true);
+    }
+
+    [Fact]
+    public void AutoDetect_OnTimeout_DoesNotFallThroughToSuccessfulDetector()
+    {
+        var document = Document(marker: true);
+        // The built-in detector is registered first; this marker is not a bend line.
+        Assert.Empty(new SolidWorksBendDetector().DetectBends(document));
+        var throwing = Register(throws: true);
+        var fallback = Register(throws: false);
+        Assert.True(BendDetectorRegistry.Detectors.ToList().IndexOf(throwing)
+            < BendDetectorRegistry.Detectors.ToList().IndexOf(fallback));
+
+        var exception = Assert.Throws<RegexMatchTimeoutException>(() => BendDetectorRegistry.AutoDetect(document));
+
+        Assert.Same(throwing.Timeout, exception);
+        Assert.Equal(1, throwing.CallCount);
+        Assert.Equal(0, fallback.CallCount);
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void Import_OnTimeout_PublishesNoResultOrRepairReportsAndPreservesSource(bool repair)
+    {
+        var path = WriteDxf("marker.dxf", marker: true);
+        var originalHash = Hash(path);
+        var detector = Register(throws: true);
+        var options = new CadImportOptions
+        {
+            BendDetectorName = detector.Name,
+            BendRepair = repair ? RepairOptions() : null,
+        };
+        var published = new List<CadImportResult>();
+        var reports = new List<BendRepairReport>();
+
+        var exception = Assert.Throws<RegexMatchTimeoutException>(() =>
+        {
+            var result = CadImporter.Import(path, options);
+            // These publication steps must be unreachable, even for an empty result.
+            published.Add(result);
+            reports.AddRange(result.BendRepairReports);
+        });
+
+        Assert.Same(detector.Timeout, exception);
+        Assert.Equal(1, detector.CallCount);
+        Assert.Empty(published);
+        Assert.Empty(reports);
+        Assert.Equal(originalHash, Hash(path));
+        // Detection precedes both repair and etch conversion in Import. No result
+        // or output escapes; do not inspect its private, disposable scratch geometry.
+        Assert.Equal(new[] { path }, Directory.GetFiles(directory));
+    }
+
+    [Fact]
+    public void ImportDrawing_AfterEarlierSuccess_AbortsBatchBeforePublication()
+    {
+        var good = WriteDxf("good.dxf", marker: false);
+        var bad = WriteDxf("marker.dxf", marker: true);
+        var hashes = new[] { Hash(good), Hash(bad) };
+        var detector = Register(throws: true);
+        var staged = new List<Drawing>();
+        var published = new List<Drawing>();
+
+        var exception = Assert.Throws<RegexMatchTimeoutException>(() =>
+        {
+            foreach (var path in new[] { good, bad })
+                staged.Add(CadImporter.ImportDrawing(path, new CadImportOptions
+                {
+                    BendDetectorName = detector.Name,
+                    BendRepair = RepairOptions(),
+                }));
+            published.AddRange(staged);
+        });
+
+        Assert.Same(detector.Timeout, exception);
+        var earlier = Assert.Single(staged);
+        Assert.Equal(good, earlier.Source.Path);
+        Assert.NotEmpty(earlier.Program.Codes);
+        // This first drawing is a discardable local, not a published batch result.
+        Assert.Empty(published);
+        Assert.Equal(1, detector.CallCount);
+        Assert.Equal(hashes, new[] { Hash(good), Hash(bad) });
+        Assert.Equal(new[] { good, bad }.Order(), Directory.GetFiles(directory).Order());
+    }
+
+    private MarkerDetector Register(bool throws)
+    {
+        var detector = new MarkerDetector(throws);
+        BendDetectorRegistry.Register(detector);
+        registered.Add(detector);
+        return detector;
+    }
+
+    private static BendRepairOptions RepairOptions() => new()
+    {
+        DrawingUnits = BendRepairUnits.Inches,
+        MaxEndpointMovementMillimeters = 2,
+    };
+
+    private string WriteDxf(string name, bool marker)
+    {
+        var path = Path.Combine(directory, name);
+        DxfWriter.Write(path, Document(marker), false);
+        return path;
+    }
+
+    private static CadDocument Document(bool marker)
+    {
+        var document = new CadDocument();
+        document.Header.InsUnits = ACadSharp.Types.Units.UnitsType.Inches;
+        document.Entities.Add(new CadLine(new XYZ(0, 0, 0), new XYZ(2, 0, 0))
+        {
+            Layer = new CadLayer(marker ? MarkerLayer : "0"),
+        });
+        document.Entities.Add(new CadLine(new XYZ(2, 0, 0), new XYZ(2, 2, 0)));
+        document.Entities.Add(new CadLine(new XYZ(2, 2, 0), new XYZ(0, 2, 0)));
+        document.Entities.Add(new CadLine(new XYZ(0, 2, 0), new XYZ(0, 0, 0)));
+        return document;
+    }
+
+    private static byte[] Hash(string path) => SHA256.HashData(File.ReadAllBytes(path));
+
+    private sealed class MarkerDetector(bool throws) : IBendDetector
+    {
+        public string Name { get; } = "RegexTimeout-" + Guid.NewGuid();
+        public bool Active { get; set; } = true;
+        public int CallCount { get; private set; }
+        public RegexMatchTimeoutException Timeout { get; } = new("marker", "<test>", TimeSpan.FromSeconds(1));
+
+        public List<Bend> DetectBends(CadDocument document)
+        {
+            if (!Active || !document.Entities.Any(e => e.Layer?.Name == MarkerLayer))
+                return new List<Bend>();
+            CallCount++;
+            if (throws)
+                throw Timeout;
+            return new List<Bend> { new() };
+        }
+    }
+}