Zscaler Security Advisories

Security Advisory - April 14, 2026

Zscaler protects against 1 new vulnerability for Adobe Acrobat and Reader

  1. Overview
  2. CVE-2026-34621 – Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').

Zscaler, working with Microsoft through their MAPP program, has proactively deployed protection for the following 1 vulnerability included in the April 2026 Adobe security bulletins. Zscaler will continue to monitor exploits associated with all vulnerabilities in the April release and deploy additional protections, as necessary.

APSB26-43 – Security updates available for Adobe Acrobat and Reader.

Adobe has released security updates for Adobe Acrobat and Reader for Windows and macOS. This update addresses a critical vulnerability. Successful exploitation could lead to arbitrary code execution. 

Affected Software

  • Acrobat DC Continuous 26.001.21367 and earlier versions for Windows & macOS
  • Acrobat Reader DC Continuous 26.001.21367 and earlier versions for Windows & macOS
  • Acrobat 2024 Classic 2024 24.001.30356 and earlier versions for Windows & macOS

CVE-2026-34621 – Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').

Severity: Critical

Subscription Required

  • Advanced Threat Protection
  • Advanced Cloud Sandbox