Is there any protection by Symantec Endpoint Protection against the threat Zero-Day - Adobe Acrobat and Reader - APSB21-29? The following link provides more information.
https://helpx.adobe.com/security/products/acrobat/apsb21-29.html
The following update now covers this threat: ISB.CVE-2021-28550!g1 release in definitions version 20210521.016