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Flaw in Adobe Extension With 300M Installs Enabled WhatsApp Data Theft

securityweek.com 2026-07-22 data leakage High

What Happened

An attacker only needed to convince the targeted user to visit a malicious website to exfiltrate WhatsApp messages and contacts. The post Flaw in Adobe Extension With 300M Installs Enabled WhatsApp Data Theft appeared first on SecurityWeek .

Why It Matters

The article reports that a UXSS-class vulnerability (CVE-2026-48294), dubbed HermeticReader, in the Adobe Acrobat Chrome extension with roughly 300M installs allowed any attacker-controlled webpage to silently exfiltrate WhatsApp Web chats, contacts, and profile information when a user visited a malicious site.[3][1] Adobe has patched the flaw in newer extension versions after disclosure by Guardio researchers.[3][1] From a RealGround perspective, this illustrates a critical browser-extension supply chain risk: widely deployed third-party components can become a high-impact data leakage vector for web apps and AI-assisted tools that rely on browser sessions. Organizations should inventory and govern browser extensions in their environment, align extension use with an SBOM-style approach, and incorporate extension-origin data exposure scenarios into AI and web-application threat models.

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RealGround Analysis

This signal maps to data leakage. Organizations using AI agents, LLM APIs, SaaS integrations, or sensitive data workflows should review whether this class of issue could create unauthorized tool execution, data leakage, weak approval gates, or unmanaged supply-chain exposure.

Recommended Actions

  • Restrict AI agent tool permissions and production write paths.
  • Review sensitive data access across prompts, logs, embeddings, memory, and SaaS integrations.
  • Add human approval workflows for high-impact or state-changing actions.
  • Run prompt injection and indirect prompt injection tests against affected workflows.
  • Document the owner, control gap, and remediation deadline for this risk class.

Source

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

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