Guardio Labs disclosed HermeticReader, a flaw chain in the Adobe Acrobat extension for Chrome that let an attacker controlled web page read data from a visitor's WhatsApp Web session. Tracked as CVE-2026-48294 and rated 7.4, it is a cross origin disclosure issue affecting versions up to 26.5.2.2, installed on roughly 329 million browsers. Any site could disguise commands as internal extension messages, activate the extension's WhatsApp integration, and redirect its privileged page operations into the WhatsApp tab, extracting chats, contacts, and message previews. No malware, stolen credentials, or WhatsApp flaw was involved. Adobe patched within days.
Google and Microsoft removed ModHeader, a header-editing browser extension popular with developers, with about 1.6 million installs, after researchers at Stripe OLT found a hidden browsing-history collector inside the official, signed store version. The collector was dormant, gated off by an empty allow-list, and no evidence has emerged that it ever sent data, but its presence in a trusted, signed extension is the concern. Its design frustrated automated review: the data was encrypted, the upload was switched off so sandboxes saw nothing leave, and malicious code was blended into a legitimate codebase, so scanners rated it low risk. It is a reminder that a store signature proves origin, not safe behavior.
Zscaler detailed Edgecution, a malicious Microsoft Edge extension used in ransomware-linked intrusions that abuses Chrome's native messaging feature, which normally lets extensions talk to desktop apps, to break out of the browser sandbox and run a Python backdoor on the host. The extension beacons to a command server and relays commands to the backdoor, giving attackers filesystem access and code execution, while running in a hidden headless browser to stay invisible. Attacks start with social engineering on Microsoft Teams, where the actor poses as IT support and directs employees to a fake "Outlook Updates" page. Researchers tie the activity to an access broker linked to the Payouts King ransomware operation.
TrustStrike Labs