diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs
index 8cb2bb6..671f3ca 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs
@@ -26,6 +26,10 @@ internal sealed class CurvatureTransition
             throw new ArgumentOutOfRangeException(nameof(localArcLengthMeters));
         }
 
+        double curvatureJumpPerMeter = Math.Abs(rightVehicleCurvaturePerMeter - leftVehicleCurvaturePerMeter);
+        if (!NumericGuard.IsFinite(curvatureJumpPerMeter))
+            throw new ArgumentOutOfRangeException(nameof(rightVehicleCurvaturePerMeter));
+
         SegmentIndex = segmentIndex;
         LeftCoarsePathIndex = leftCoarsePathIndex;
         RightCoarsePathIndex = rightCoarsePathIndex;
@@ -35,7 +39,7 @@ internal sealed class CurvatureTransition
         VehicleHeadingRadians = vehicleHeadingRadians;
         LeftVehicleCurvaturePerMeter = leftVehicleCurvaturePerMeter;
         RightVehicleCurvaturePerMeter = rightVehicleCurvaturePerMeter;
-        CurvatureJumpPerMeter = Math.Abs(rightVehicleCurvaturePerMeter - leftVehicleCurvaturePerMeter);
+        CurvatureJumpPerMeter = curvatureJumpPerMeter;
     }
 
     internal int SegmentIndex { get; }
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs
index b2a10ef..54d95ba 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs
@@ -46,6 +46,11 @@ internal sealed class CurvatureTransitionDetector
                 CoarsePathPoint left = request.CoarsePath[leftIndex];
                 CoarsePathPoint right = request.CoarsePath[leftIndex + 1];
                 double delta = right.VehicleCurvature - left.VehicleCurvature;
+                if (!NumericGuard.IsFinite(delta))
+                {
+                    reason = "局部 G2 曲率事件跳变溢出。";
+                    return false;
+                }
                 if (Math.Abs(delta) >= threshold)
                 {
                     detected.Add(new CurvatureTransition(
diff --git a/ClumsyPilot/tests/verify_path_smoothing_local_g2_detection.ps1 b/ClumsyPilot/tests/verify_path_smoothing_local_g2_detection.ps1
index d35eff4..7b82cd9 100644
--- a/ClumsyPilot/tests/verify_path_smoothing_local_g2_detection.ps1
+++ b/ClumsyPilot/tests/verify_path_smoothing_local_g2_detection.ps1
@@ -7,6 +7,10 @@ function Assert-True($Actual, [string]$Message) {
     if (-not $Actual) { throw $Message }
 }
 
+function Assert-False($Actual, [string]$Message) {
+    if ($Actual) { throw $Message }
+}
+
 function Assert-Equal($Expected, $Actual, [string]$Message) {
     if ($Expected -ne $Actual) { throw "$Message Expected=$Expected Actual=$Actual" }
 }
@@ -55,4 +59,38 @@ Assert-Near 0.0 $nearStart.StartArcLength 0.000000001 'A start window must be cl
 Assert-True ($nearStart.RightWindowLength -gt $nearStart.LeftWindowLength) `
     'Unavailable left length must be shifted to the right.'
 
+# Finite endpoint curvatures may still overflow during subtraction; detection must fail rather than publish infinity.
+$coarsePathPointType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.CoarsePath.CoarsePathPoint'
+$pathSegmentType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.CoarsePath.PathSegment'
+$directionType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.CoarsePath.TravelDirection'
+$coarseSourceType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.CoarsePath.CoarsePathPointSource'
+$requestType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.PathSmoothing.PathSmoothingRequest'
+$configurationType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.PathSmoothing.PathSmoothingConfiguration'
+$optionsType = Get-RequiredType 'MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2.LocalG2OptionsSnapshot'
+$forward = [Enum]::Parse($directionType, 'Forward')
+$motionPrimitive = [Enum]::Parse($coarseSourceType, 'MotionPrimitive')
+$overflowPoints = [Array]::CreateInstance($coarsePathPointType, 2)
+$overflowPoints.SetValue([Activator]::CreateInstance($coarsePathPointType, @(
+    [double]0.0, [double]0.0, [double]0.0, [double]0.0, [double]0.0, $forward,
+    -[double]::MaxValue, [double]1.0, $false, $motionPrimitive)), 0)
+$overflowPoints.SetValue([Activator]::CreateInstance($coarsePathPointType, @(
+    [double]0.1, [double]0.0, [double]0.0, [double]0.0, [double]0.1, $forward,
+    [double]::MaxValue, [double]1.0, $false, $motionPrimitive)), 1)
+$overflowSegments = [Array]::CreateInstance($pathSegmentType, 1)
+$overflowSegments.SetValue([Activator]::CreateInstance($pathSegmentType, @(0, $forward, 0, 1, $false, $false)), 0)
+$configuration = [Activator]::CreateInstance($configurationType)
+$optionsConstructor = $optionsType.GetConstructor([Reflection.BindingFlags]'Instance,NonPublic', $null, @($configurationType), $null)
+Assert-True ($null -ne $optionsConstructor) 'Local G2 options must be constructible for detector reflection tests.'
+$options = $optionsConstructor.Invoke(@($configuration))
+$overflowRequest = [Activator]::CreateInstance($requestType, @($overflowPoints, $overflowSegments, $null, $null, $configuration))
+$detector = [Activator]::CreateInstance($detectorType, $true)
+$tryDetect = $detectorType.GetMethod('TryDetect', [Reflection.BindingFlags]'Instance,NonPublic')
+Assert-True ($null -ne $tryDetect) 'CurvatureTransitionDetector must retain its internal TryDetect contract.'
+$overflowArguments = [object[]]@($overflowRequest, [double]0.8333, $options, $null, $null)
+$overflowAccepted = $tryDetect.Invoke($detector, $overflowArguments)
+Assert-False $overflowAccepted 'Curvature subtraction overflow must reject detection.'
+Assert-True (-not [string]::IsNullOrWhiteSpace([string]$overflowArguments[4])) `
+    'Rejected overflow detection must provide a stable reason.'
+Assert-Equal 0 $overflowArguments[3].Count 'Rejected overflow detection must not publish a curvature event.'
+
 Write-Output 'Path smoothing Local G2 detection checks passed.'