Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by an out-of-bounds read vulnerability that could lead to disclosure of arbitrary memory information in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-39861
• https://helpx.adobe.com/security/products/acrobat/apsb21-55.html