CVE-2026-96396: Buffer Overflow
The Affinity by Canva application for macOS before 3.3.1 (October 2026 release) did not safely calculate the size of an image buffer when generating QuickLook thumbnails and previews of Affinity document files, leading to an integer overflow and a heap-based buffer overflow. A threat actor could craft an Affinity document that, when displayed or previewed by a user in Finder, could corrupt heap memory and cause the thumbnail or preview extension to crash.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Affinity by Canva for macOSto a version that resolves this vulnerability.Fixed in 3.3.1
Event History
Frequently Asked Questions
Who is exposed to this issue?
macOS users running Affinity by Canva versions earlier than 3.3.1 are exposed when Finder generates a QuickLook thumbnail or preview for an Affinity document file.
What does an attacker need to do to trigger the flaw?
An attacker needs to provide a crafted Affinity document that is displayed or previewed in Finder. No user interaction beyond causing Finder to display or preview the document is described.
What is the known impact of successful exploitation?
The crafted document can cause an integer overflow followed by a heap-based buffer overflow in the thumbnail or preview extension. The described outcome is heap-memory corruption and a crash of that extension.
How can I determine whether my installation is affected?
Check the installed Affinity by Canva version on macOS. Versions before 3.3.1 are affected; the issue is addressed in the October 2026 3.3.1 release.