In 2026, the web browser has become the convergence point for all professional usage: access to SaaS applications, interactions with generative AI tools, identity management, and sensitive data handling. Yet it remains largely outside the field of vision of traditional security architectures.

A structural blind spot in your defense layers

DLP, EDR, and SSE solutions were designed to monitor file transfers and endpoints. They cannot see what happens inside an active browsing session. The most common exfiltrations today no longer go through detectable file transfers — they happen through simple copy-paste actions into an AI chat window, or through third-party extensions with broad permissions operating silently in the background.

85% of the workday now takes place inside a browser. That is where your data, your authenticated sessions, and your digital identities reside — and that is precisely where attackers are focusing their efforts.

Session hijacking: the new primary attack vector

Groups like Scattered Spider have industrialized the theft of cookies and authentication tokens stored in browser memory. Once these elements are compromised, MFA becomes ineffective: the attacker gains direct access to Office 365, Google Workspace, or your critical business tools — without credentials, without alerts, and without a trace in your usual logs.

At the same time, 68% of enterprise connections occur outside SSO, and 43% of SaaS applications are accessed through personal accounts — creating structural Shadow IT that entirely escapes your oversight.

Extensions: an uncontrolled supply chain

99% of enterprise users have at least one extension installed in their browser. More than half have high or critical permissions: cookie access, keystroke capture, data access across all visited sites. The 2024 Cyberhaven extension attack is the most striking example: a legitimate extension, compromised upstream, automatically updated to exfiltrate session tokens at scale — without triggering a single alert.

Embedded AI: a new exposure surface

Next-generation browsers integrating AI capabilities (automatic tab reading, content summarization, session context access) create exfiltration vectors toward external cloud models that escape all conventional controls. Add to this the zero-day vulnerabilities targeting the Chromium engine (such as CVE-2025-6558), enabling sandbox escape through a simple visit to a malicious page.

In conclusion, security posture must be rethought around the browser. In the face of these threats, a peripheral response is no longer sufficient. The browser is now your new perimeter. It is time to treat it as such.