@@ -1560,6 +1560,11 @@ private int ReadImageHeaders(BufferedReadStream stream, out bool inverted, out b
             this.infoHeader.Height = -this.infoHeader.Height;
         }
 
+        if (this.infoHeader.Width <= 0 || this.infoHeader.Height <= 0)
+        {
+            BmpThrowHelper.ThrowInvalidImageContentException("Width and height must be greater than 0.");
+        }
+
         int bytesPerColorMapEntry = 4;
         int colorMapSizeBytes = -1;
         if (this.infoHeader.ClrUsed == 0)
 
@@ -261,11 +261,6 @@ protected override ImageInfo Identify(BufferedReadStream stream, CancellationTok
             this.currentLocalColorTable?.Dispose();
         }
 
-        if (this.logicalScreenDescriptor.Width == 0 && this.logicalScreenDescriptor.Height == 0)
-        {
-            GifThrowHelper.ThrowNoHeader();
-        }
-
         // Ignoring a malformed ancillary extension must not let identify succeed for a file
         // that never contained any readable image frame data.
         if (previousFrame is null)
@@ -328,6 +323,10 @@ private void ReadLogicalScreenDescriptor(BufferedReadStream stream)
         }
 
         this.logicalScreenDescriptor = GifLogicalScreenDescriptor.Parse(this.buffer);
+        if (this.logicalScreenDescriptor.Width == 0 || this.logicalScreenDescriptor.Height == 0)
+        {
+            GifThrowHelper.ThrowInvalidImageContentException("Width and height must be greater than 0.");
+        }
     }
 
     /// <summary>
 
@@ -72,9 +72,9 @@ protected override Image<TPixel> Decode<TPixel>(BufferedReadStream stream, Cance
                 TgaThrowHelper.ThrowNotSupportedException($"Unknown tga colormap type {this.fileHeader.ColorMapType} found");
             }
 
-            if (this.fileHeader.Width == 0 || this.fileHeader.Height == 0)
+            if (this.fileHeader.Width <= 0 || this.fileHeader.Height <= 0)
             {
-                throw new UnknownImageFormatException("Width or height cannot be 0");
+                TgaThrowHelper.ThrowInvalidImageContentException("Width and height must be greater than 0.");
             }
 
             Image<TPixel> image = new(this.configuration, this.fileHeader.Width, this.fileHeader.Height, this.metadata);
 
@@ -0,0 +1,18 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+namespace SixLabors.ImageSharp.Tests.Formats;
+
+public class InvalidImageDimensionsTests
+{
+    [Theory]
+    [InlineData("Qk1GAAAAAAAAADYAAAAoAAAAAgACAAAAAAABABgAAAAAABAAAAATCwAAEwsAAAAAAAAAAAAAAAD/AP8AAAAAAP8A/wAAAA==")]
+    [InlineData("R0lGODdhAgIAAIEAAAD/AP8AAAAA/wAAACwAAAQAAgACAAAIBwADABAQICAAOw==")]
+    [InlineData("AAACAAAAAAAAAAAAAgDCsRgAAgAAAP8A/wD/AAAA//8=")]
+    public void Load_WithNonPositiveDimensions_ThrowsInvalidImageContentException(string encodedData)
+    {
+        byte[] data = Convert.FromBase64String(encodedData);
+
+        Assert.Throws<InvalidImageContentException>(() => Image.Load(data));
+    }
+}
Original file line number	Diff line number	Diff line change
`@@ -261,11 +261,6 @@ protected override ImageInfo Identify(BufferedReadStream stream, CancellationTok`
`261`	`261`	`this.currentLocalColorTable?.Dispose();`
`262`	`262`	`}`
`263`	`263`
`264`		`- if (this.logicalScreenDescriptor.Width == 0 && this.logicalScreenDescriptor.Height == 0)`
`265`		`- {`
`266`		`- GifThrowHelper.ThrowNoHeader();`
`267`		`- }`
`268`		`-`
`269`	`264`	`// Ignoring a malformed ancillary extension must not let identify succeed for a file`
`270`	`265`	`// that never contained any readable image frame data.`
`271`	`266`	`if (previousFrame is null)`
`@@ -328,6 +323,10 @@ private void ReadLogicalScreenDescriptor(BufferedReadStream stream)`
`328`	`323`	`}`
`329`	`324`
`330`	`325`	`this.logicalScreenDescriptor = GifLogicalScreenDescriptor.Parse(this.buffer);`
	`326`	`+ if (this.logicalScreenDescriptor.Width == 0 \|\| this.logicalScreenDescriptor.Height == 0)`
	`327`	`+ {`
	`328`	`+ GifThrowHelper.ThrowInvalidImageContentException("Width and height must be greater than 0.");`
	`329`	`+ }`
`331`	`330`	`}`
`332`	`331`
`333`	`332`	`/// <summary>`
Original file line number	Diff line number	Diff line change
`@@ -72,9 +72,9 @@ protected override Image<TPixel> Decode<TPixel>(BufferedReadStream stream, Cance`
`72`	`72`	`TgaThrowHelper.ThrowNotSupportedException($"Unknown tga colormap type {this.fileHeader.ColorMapType} found");`
`73`	`73`	`}`
`74`	`74`
`75`		`- if (this.fileHeader.Width == 0 \|\| this.fileHeader.Height == 0)`
	`75`	`+ if (this.fileHeader.Width <= 0 \|\| this.fileHeader.Height <= 0)`
`76`	`76`	`{`
`77`		`- throw new UnknownImageFormatException("Width or height cannot be 0");`
	`77`	`+ TgaThrowHelper.ThrowInvalidImageContentException("Width and height must be greater than 0.");`
`78`	`78`	`}`
`79`	`79`
`80`	`80`	`Image<TPixel> image = new(this.configuration, this.fileHeader.Width, this.fileHeader.Height, this.metadata);`