Acrobat Reader versions 24.001.30307, 24.001.30308, 25.001.21265 and earlier are affected by an Improper Certificate Validation vulnerability that could result in a Security feature bypass. An attacker could leverage this vulnerability to spoof the identity of a signer. Exploitation of this issue requires user interaction.
https://helpx.adobe.com/security/products/acrobat/apsb26-26.html