HermeticReader is the name given to a recently disclosed vulnerability in the Adobe Acrobat PDF extension for Chrome, tracked as CVE-2026-48294.
Researchers discovered the issue in early June 2026 and reported it to Adobe, which patched the flaw over a single weekend. They found that a single visit to a malicious website could turn Adobe’s Acrobat Chrome browser extension into a silent spy on your WhatsApp Web conversations.
The exploit worked across platforms, meaning any Windows, macOS, Linux, or ChromeOS device was potentially vulnerable if it met three conditions:
It used Google Chrome or another Chromium-based browser compatible with Chrome extensions, which account for around 78% of the browser market.
It had the vulnerable Adobe Acrobat PDF extension installed and enabled. The extension has reportedly been installed on around 329 million browsers.
