In today’s fast-paced digital workplace, browser extensions have become indispensable productivity enhancers. From grammar checkers and password managers to cutting-edge generative AI assistants, these small add‑ons embed themselves into employees’ daily workflows with remarkable ease. However, behind the convenience lies a growing cybersecurity blind spot. Many organizations underestimate the potential risks associated with browser extensions risks that span data exfiltration, unauthorized access to sensitive information, and unvetted code running on corporate endpoints.

LayerX’s recently released Enterprise Browser Extension Security Report 2025 is the first study to combine public marketplace data with in‑house enterprise telemetry, offering a comprehensive view of extension usage across large organizations. By correlating download statistics, permission scopes, publisher reputations, and update cadences, the report illuminates a threat surface that frequently escapes the attention of even the most vigilant IT and security teams. In this expanded rewrite, we’ll delve into the report’s most compelling insights, explore why each finding matters, and outline actionable steps organizations can take to fortify their defences against extension‑based threats.

Browser Extensions: The Silent Workforce Allies

Defining the Extension Ecosystem

Browser extensions are lightweight pieces of software that modify or augment browsing experiences. They install directly into web browsers—Chrome, Edge, Firefox, and others—to provide features ranging from ad blocking to real‑time language translation. Because they operate within the browser sandbox, extensions can interact with web content, cookies, form fields, and network requests. This close integration is what makes them powerful productivity tools—and, simultaneously, high‑value targets for attackers seeking to intercept data or inject malicious scripts.

Ubiquity in the Enterprise

According to LayerX’s telemetry, 99% of employees within surveyed organizations have at least one browser extension installed, and 52% maintain more than ten. This near‑universal adoption underscores how extensions have woven themselves into the fabric of daily work: whether a developer uses GitHub helpers, a marketer leverages SEO optimization tools, or an HR professional relies on scheduling add‑ons. Yet this ubiquity also means that the average enterprise endpoint hosts a diverse—and often unmanaged—collection of third‑party code.

Key Findings from the Enterprise Browser Extension Security Report 2025

1. Widespread Permission Overreach

LayerX discovered that 53% of all installed extensions grant access to sensitive data categories, including cookies, saved passwords, browsing history, and page contents. In practice, this means that a malicious or compromised extension could siphon login tokens, harvest form data, or monitor every page an employee visits. Because many users accept permission requests without scrutiny—often trusting that major marketplace reviews suffice—organizations may unknowingly expose critical credentials and proprietary information to third parties.

2. Publisher Trust Deficit

The report highlights a startling statistic: 54% of extension publishers lack a verifiable identity beyond a generic Gmail address, and 79% of all publishers have released only a single extension. This fragmentation makes it exceedingly difficult for IT teams to conduct meaningful reputation checks. Without a centralized publisher registry or robust vetting processes on public extension stores, the line between legitimate developers and threat actors becomes blurred. Enterprises face a daunting challenge in distinguishing well‑maintained, reputable extensions from potentially malicious or abandoned ones.

3. The Rise of GenAI Extensions

Generative AI has surged into mainstream usage, and browser extensions are no exception. Over 20% of enterprise users leverage at least one GenAI add‑on for tasks such as drafting emails, summarizing content, or generating code snippets. Crucially, 58% of these extensions request high‑risk permissions—often including the ability to read and modify all web pages. Given the sensitive nature of enterprise data, this combination of advanced AI capabilities and broad access can accelerate data leakage if not adequately monitored and controlled.

4. Unmaintained and Sideloaded Extensions

Maintenance gaps represent another critical vulnerability. The report finds that 51% of extensions in enterprise environments have not received updates in over twelve months. Unpatched code may contain known vulnerabilities or security flaws that threat actors can exploit. Additionally, 26% of enterprise extensions are sideloaded—installed outside of official stores—thus bypassing baseline security checks and review policies. Sideloaded extensions often originate from private distribution channels or manual installations, making them much harder for centralized IT policies to detect or revoke.

Why These Findings Matter

Enterprise endpoints serve as gateways to a company’s most valuable assets: customer data, intellectual property, and internal communications. Extensions operate within this gateway, often with elevated privileges. An attacker who compromises an extension—or masquerades a malicious extension as a productivity tool—can execute stealthy reconnaissance, inject fraudulent content, and extract sensitive information without triggering traditional antivirus or network‑based detection. As organizations accelerate their shift to remote and hybrid work models, reliance on browser‑based workflows only intensifies this exposure.

Best Practices and Recommendations for IT and Security Teams

The true power of the Enterprise Browser Extension Security Report lies not just in its diagnostics but also in its prescriptive guidance. Below, we outline a strategic roadmap—based on LayerX’s five key recommendations—for transforming a fragmented extension landscape into a managed, risk‑reduced environment.

Audit All Installed Extensions

A comprehensive inventory forms the backbone of any security initiative. Begin by leveraging browser management APIs and endpoint management solutions to enumerate every extension installed across your user base. Include both official store installs and sideloaded add‑ons. Collect metadata such as extension IDs, version numbers, permission scopes, installation dates, and publisher details. This unified dataset will serve as the single source of truth for subsequent risk assessments and policy enforcement.

Categorize Extensions by Function and Risk Profile

Not all extensions present equal risk. Classify add‑ons according to their primary function—productivity, security, AI assistance, media management, and so forth—and map each category to a preliminary risk tier. For example, GenAI and data‑scraping tools may inherently require broader permissions, placing them into a higher scrutiny bucket. Conversely, UI‑only extensions (such as dark‑mode toggles) may pose a minimal threat if they limit themselves to the presentation logic. This categorization helps IT leaders prioritize oversight and allocate resources effectively.

Enumerate and Analyze Permission Scopes

With an inventory in hand, drill down into each extension’s declared permissions. Focus on the most sensitive flags—“read and change all data on websites you visit,” “access your browsing history,” and “manage downloads”—but don’t overlook less obvious scopes like “nativeMessaging” or “cookies.” Create a permission‑centric risk matrix that correlates specific scopes with potential impact. For instance, the combination of “cookies” and “history” access could enable session hijacking, while “webRequest” permissions may permit request manipulation or injection of malicious payloads.

Assess Extension Risk Holistically

The risk assessment must encompass technical permissions as well as broader factors, such as publisher reputation, update frequency, user adoption rates, and marketplace ratings. Assign each extension a composite risk score that weights these parameters. Extensions from unknown publishers with outdated versions, requesting high‑impact permissions, and installed on a significant fraction of endpoints should trigger high‑risk alerts. Modern security platforms can automate this scoring, generating dynamic dashboards that surface emergent threats in real-time.

Implement Adaptive, Risk‑Based Enforcement Policies

Armed with a nuanced risk profile for every extension, organizations can move beyond blanket allowlists or denylists. Instead, apply adaptive policies tailored to user roles, departments, or sensitivity levels. Automatic approval workflows may suffice for low-risk productivity tools. High‑risk add‑ons—particularly those requesting extensive web access or from unverified publishers—should require manual review by security teams or be restricted to specific user cohorts (for example, developers in sandboxed environments). Continuous monitoring and automated remediation (such as forced uninstallation) ensure that policy compliance keeps pace with new installs and version updates.

Additional Mitigation Strategies

While the five‑step framework provides a solid foundation, forward‑looking organizations can adopt supplementary techniques to harden their extension security posture further:

Deploy Browser Isolation: Use containerized or virtual browsing environments to execute untrusted extensions in isolation, preventing them from touching corporate networks or data stores.
Leverage Enterprise‑Grade Management Consoles: Platforms like Google Workspace for Chrome Enterprise or Microsoft Intune offer granular controls over extension policies, including force‑install, blocklist, and allowlist features.
Establish User Education Programs: Train employees to recognize excessive permission requests, verify publisher identities, and report suspicious behaviours. Human awareness remains a critical defence layer.
Integrate Extension Monitoring with SIEM: Forward extension install/uninstall events, permission changes, and update logs into security information and event management (SIEM) systems for correlation with broader threat indicators.
Run Periodic Security Audits: Schedule quarterly reviews of extension inventories, risk scores, and policy effectiveness to adapt to evolving threat landscapes and business needs.

Conclusion

Browser extensions, once a niche convenience, now power essential functions across nearly every enterprise. Their deep integration into web workflows and expansive permission scopes create an attractive attack surface for adversaries. LayerX’s Enterprise Browser Extension Security Report 2025 delivers a data‑driven wake‑up call: without proactive auditing, categorization, and risk‑based enforcement, organizations risk leaving their most sensitive assets exposed via overlooked browser add‑ons.

New Report Reveals Risks of Browser Extensions to Enterprise Data