SixLabors/ImageSharp · error · InvalidImageContentException

(invalid memory operation)

Error message

{this.Dimensions} (invalid memory operation)

What it means

During Identify, ImageDecoderCore catches InvalidMemoryOperationException thrown by decoders when the image header implies buffers/dimensions that violate memory bounds, and rethrows it as InvalidImageContentException carrying the image dimensions. It signals the file declares sizes or layout that cannot be safely allocated.

Solutions

  1. Catch InvalidImageContentException around Identify and treat the file as unidentifiable/corrupt
  2. Pre-check file size and magic bytes so obviously truncated files are rejected before decoding
  3. Re-obtain the file from a trusted source and verify its integrity
  4. If dimensions are the concern, validate MaxWidth/MaxHeight options or pre-read header bounds

Example fix

// before
var info = Image.Identify(stream); // InvalidImageContentException
// after
try { var info = Image.Identify(stream); }
catch (InvalidImageContentException ex) { logger.LogWarning(ex, "Corrupt image"); }
Defensive patterns

Strategy: try-catch

Validate before calling

if (fileInfo.Length < 64) throw new InvalidOperationException("File too small to be a valid image.");

Try / catch

try { var info = Image.Identify(stream); }
catch (InvalidImageContentException ex)
{
    // header implies invalid memory operation — treat as corrupt
    return Result.Corrupt;
}

Prevention

When it happens

Trigger: Calling Image.Identify/IdentifyAsync on a file whose header claims extreme dimensions, invalid component counts, or out-of-bounds offsets causing InvalidMemoryOperationException inside the format decoder.

Common situations: Corrupt or hostile images crafted to declare huge dimensions; truncated files where header fields are garbage; images produced by buggy encoders with inconsistent metadata.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of SixLabors/ImageSharp@59ce6af6fc (2026-09-13). Data as JSON: /api/errors/1dec5d69616841c0. Report an issue: GitHub.

Appendix: source

Thrown at src/ImageSharp/Formats/ImageDecoderCore.cs:125

    /// <param name="configuration">The shared configuration.</param>
    /// <param name="stream">The <see cref="Stream" /> containing image data.</param>
    /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
    /// <returns>The <see cref="ImageInfo" />.</returns>
    /// <exception cref="InvalidImageContentException">Thrown if the encoded image contains errors.</exception>
    public ImageInfo Identify(
        Configuration configuration,
        Stream stream,
        CancellationToken cancellationToken)
    {
        using BufferedReadStream bufferedReadStream = new(configuration, stream, cancellationToken);

        try
        {
            return this.Identify(bufferedReadStream, cancellationToken);
        }
        catch (InvalidMemoryOperationException ex)
        {
            throw new InvalidImageContentException(this.Dimensions, ex);
        }
        catch (Exception)
        {
            throw;
        }
    }

    /// <summary>
    /// Decodes the image from the specified stream to an <see cref="Image{TPixel}" /> of a specific pixel type.
    /// </summary>
    /// <typeparam name="TPixel">The pixel format.</typeparam>
    /// <param name="configuration">The shared configuration.</param>
    /// <param name="stream">The <see cref="Stream" /> containing image data.</param>
    /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
    /// <returns>The <see cref="Image{TPixel}" />.</returns>
    /// <exception cref="InvalidImageContentException">Thrown if the encoded image contains errors.</exception>
    public Image<TPixel> Decode<TPixel>(
        Configuration configuration,

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