gchq/CyberChef · error · OperationError

Invalid file type.

Error message

Invalid file type.

What it means

BlurImage runs an isImage() check on the input ArrayBuffer before processing. If the bytes are not recognized as a supported image type it throws 'Invalid file type.' immediately, before Jimp is invoked.

Source

Thrown at src/core/operations/BlurImage.mjs:56

            },
            {
                name: "Type",
                type: "option",
                value: ["Fast", "Gaussian"],
            },
        ];
    }

    /**
     * @param {ArrayBuffer} input
     * @param {Object[]} args
     * @returns {byteArray}
     */
    async run(input, args) {
        const [blurAmount, blurType] = args;

        if (!isImage(input)) {
            throw new OperationError("Invalid file type.");
        }

        let image;
        try {
            image = await Jimp.read(input);
        } catch (err) {
            throw new OperationError(`Error loading image. (${err})`);
        }
        try {
            switch (blurType) {
                case "Fast":
                    if (isWorkerEnvironment())
                        self.sendStatusMessage("Fast blurring image...");
                    image.blur(blurAmount);
                    break;
                case "Gaussian":
                    if (isWorkerEnvironment())
                        self.sendStatusMessage("Gaussian blurring image...");

View on GitHub (pinned to 4290ea7539)

Solutions

1. Confirm the input is a supported image (PNG/JPEG/BMP/etc.) by checking magic bytes before invoking.
2. Re-fetch or re-export the file if it may be truncated.
3. Route non-image files to the correct operation instead of BlurImage.

Example fix

// before
BlurImage.run(textBuffer, args)
// after
BlurImage.run(pngBuffer, args)

if (!isImage(input)) throw new Error('Input is not a supported image');

function isLikelyImage(buf) { return isImage(buf) !== false; }

try { blurImage.run(input, args); }
catch (e) { if (/Invalid file type/.test(e.message)) { /* route to correct op */ } else throw e; }

When it happens

Trigger: Calling BlurImage.run with an input ArrayBuffer whose magic bytes are not a supported image format (e.g. a text file, PDF, or corrupted header).

Common situations: Piping non-image data into the operation; uploading the wrong file; truncated download whose magic bytes are gone; a format isImage() does not recognize.

Related errors

• Invalid file type.
• Invalid file type.
• Invalid file type.
• Unsupported file type (supported: jpg,png,pbm,bmp) or no fil
• Invalid file type.

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/c534557a06d9984f. Report an issue: GitHub.