Adobe Acrobat Reader DC version 21.007.20095 (and earlier), 21.007.20096 (and earlier), 20.004.30015 (and earlier), and 17.011.30202 (and earlier) is affected by a out-of-bounds read vulnerability that could lead to disclosure of sensitive memory. An attacker could leverage this vulnerability to bypass mitigations such as ASLR. Exploitation of this issue requires user interaction in that a victim must open a malicious PDF file.
https://helpx.adobe.com/security/products/acrobat/apsb21-104.html