Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by an Information Exposure vulnerability. An unauthenticated attacker could leverage this vulnerability to get access to restricted data stored within global variables and objects.
https://helpx.adobe.com/security/products/acrobat/apsb21-29.html