CVE-2026-48294: Adobe Acrobat Chrome Extension — WhatsApp Data Exfiltration Risk (June 2026)

CVE-2026-48294 — Adobe Acrobat Chrome Extension

CVE-2026-48294 is a high-severity vulnerability in the Adobe Acrobat Chrome extension, affecting approximately 329 million browser installations globally. The flaw allowed attackers to exfiltrate WhatsApp messages, contacts, and account details in plain text by luring users to malicious websites. No malware deployment or credential compromise was required. Adobe released a patch in June 2026 following coordinated disclosure by Guardio researchers. No evidence of widespread exploitation prior to patch release has been reported.

Attack Vector

Attackers crafted malicious websites that leveraged the vulnerable Adobe Acrobat Chrome extension to access data from WhatsApp Web sessions running in the same browser. By exploiting insecure extension permissions and inter-process communication, attackers could read and exfiltrate WhatsApp chat content, contacts, and account metadata without user interaction beyond visiting a crafted URL. No additional payloads or downloads were necessary, and the attack left minimal forensic artifacts, complicating detection.

Who Is at Risk

All users and organizations with the Adobe Acrobat Chrome extension installed prior to June 2026 are at risk, regardless of operating system or geography. The vulnerability impacts both enterprise-managed and unmanaged endpoints. Adobe is the primary affected vendor; any organization with widespread Chrome extension deployments should assume exposure until patched. WhatsApp Web users are specifically targeted, but any sensitive browser session data could be at risk if similar flaws exist.

Patch & Mitigate

• Patch: Update the Adobe Acrobat Chrome extension to the version released in June 2026 or later. Immediate deployment is critical.
• Workaround: Temporarily disable or remove the extension if patching is not feasible.
• Detect: Review browser extension logs for unexpected access to WhatsApp Web domains. Monitor outbound traffic for unauthorized data exfiltration to suspicious domains following user visits to unfamiliar sites.

MITRE ATT&CK

• TA0005 — Defense Evasion: Attackers abused browser extension permissions to bypass traditional endpoint defenses and access session data.
• T1185 — Browser Session Hijacking: The vulnerability enabled unauthorized access to active WhatsApp Web sessions within the browser.

Source: https://www.securityweek.com/flaw-in-adobe-extension-with-300m-installs-enabled-whatsapp-data-theft/