CVE-2020-35931

An issue was discovered in Foxit Reader before 10.1.1 (and before 4.1.1 on macOS) and PhantomPDF before 9.7.5 and 10.x before 10.1.1 (and before 4.1.1 on macOS). An attacker can spoof a certified PDF document via an Evil Annotation Attack because the products fail to consider a null value for a Subtype entry of the Annotation dictionary, in an incremental update.

Source: CVE-2020-35931