Ravie LakshmananJul 22, 2026Vulnerability / Browser Security
Cybersecurity researchers have disclosed details of a now-patched vulnerability chain in the Adobe Acrobat Chrome extension that has over 314 million users, which, if exploited, could facilitate a silent hijack of a user's WhatsApp data.
The shortcoming has been codenamed HermeticReader by Guardio Labs. It's officially tracked as CVE-2026-48294 (CVSS score: 7.4), with the vulnerability described as a case of universal cross-site scripting (UXSS)-class cross-origin data disclosure vulnerability. It affects all versions of the extension (ID: efaidnbmnnnibpcajpcglclefindmkaj) prior to and including 26.5.2.2.
Successful exploitation of the flaw can bypass the browser's same-origin policy and access data linked to the victim's session across origins. The only prerequisite is that it requires user interaction. A victim must be convinced into visiting a maliciously crafted URL or interact with a compromised web page that triggers the extension's vulnerable code path.
In other words, an attacker can weaponize the flaw to obtain cross-origin read access to session-bound data. This can include authenticated content from third-party web applications loaded in the victim's browser.
