The Affinity by Canva app for macOS before 3.3.1 (October 2026 release) did not perform adequate bounds checking when generating QuickLook thumbnails and previews of Affinity document files, leading to an out-of-bounds heap read. A threat actor could craft an Affinity document that, when displayed or previewed by a user in Finder, could disclose the contents of adjacent heap memory, including memory addresses, in the rendered thumbnail or preview image.