Adobe rolls out emergency fix for Acrobat, Reader zero-day flaw

Adobe released emergency updates for CVE-2026-34621, a zero-day in Acrobat/Reader exploited in the wild by malicious PDFs that bypass sandbox restrictions and invoke privileged JavaScript APIs (e.g., util.readFileIntoStream, RSS.addFeed) to read and exfiltrate local files without further user interaction; attacks were observed since at least December and Adobe has published fixes for affected Windows and macOS versions—apply updates immediately.