WhatsApp Security Alert: CISA Warns of Zero-Day Flaw Allowing Hackers to Steal Data Without User Interaction

The Cybersecurity and Infrastructure Security Agency (CISA) has issued an alert after including a significant WhatsApp vulnerability in its Known Exploited Vulnerabilities (KEV) record. The issue, identified as CVE-2025-55177, is already in use by hackers and has been classified as a serious threat.  CISA has given federal agencies and crucial organizations until September 23 to fix the issue.

The vulnerability affects WhatsApp's connected device feature, which allows users to utilize the same account on numerous devices simultaneously.While this feature is appreciated for its ease, it also presents a difficulty.The issue arises from an incorrect authorization check in the way WhatsApp synchronizes messages between devices.This vulnerability allows attackers to trick the system and submit malicious requests that the app mistakenly responds to.

This new WhatsApp issue is especially concerning since hackers can target accounts without you having to click a link or download anything. Instead, they can exploit the way WhatsApp connects many devices to mislead the system into accepting malicious data from fraudulent sources. Once in, the attackers can do far more than just break into your account.They may steal your information, read your chats, copy your contacts, or even install malware to secretly monitor your activities. Even worse, they can remain hidden inside your devices for an extended period of time without your knowledge. Because WhatsApp is used by billions of people globally, the potential impact of such incidents is enormous, not only for individuals, but also for businesses and organizations that rely on the application for daily communication.

CISA's decision to rapidly add this WhatsApp flaw to its Known Exploited Vulnerabilities (KEV) list demonstrates how important and urgent the situation is. By publicly categorizing it as a high-risk vulnerability and setting a fixed deadline for remediation, the agency is emphasizing the importance of fast action in preventing widespread damage. For ordinary WhatsApp users, the best prevention is simple but crucial that always keep the app updated, update security patches as soon as they become available, and be watchful for any official updates from the platform. Regular updates may appear regularly, but in situations like this, they are the most effective security against attackers attempting to exploit such dangerous defects.

This event is simply another reminder that even the most reputable and frequently used apps can contain hidden flaws. In today's rapidly evolving cybersecurity world, staying informed and knowledgeable is the best way to mitigate risks.

Information referenced in this article is from Cyber Press