Lychee: A single 383-byte PDF causes ~184 seconds of CPU consumption in the real processing path

Lychee is a free, open-source photo-management tool. Prior to 7.7.0, Lychee enables ImageMagick PDF support with Ghostscript but does not apply an effective pre-render limit to PDF page dimensions in ImagickHandler::loadPdf(). An authenticated user who can upload a small PDF with an oversized /MediaBox can cause Imagick::readImage() to consume substantial CPU before failing to produce an image. When QUEUE_CONNECTION selects synchronous processing the request can occupy a web worker, while the official asynchronous Docker configuration can clog the shared image-processing queue and delay other work. The advisory did not identify a Ghostscript sandbox escape. This issue is fixed in version 7.7.0.