Browser Security Startup cside Gains Traction as Client-Side Threats Surge

NEW YORK, NY – November 18, 2025 – As traditional cybersecurity defenses prove insufficient against evolving threats, a new category of security solutions focused on the browser itself is gaining momentum. cside, a Delaware-based startup specializing in client-side protection, is rapidly emerging as a key player in this space. The company recently secured three industry awards – ‘Client-Side Protection’ from Cyber Defense Awards, a ‘top performer in Client-Side Security’ from SourceForge, and a ‘Stellar Startup’ award from CRN – signaling growing recognition of its innovative approach.

The Rise of Client-Side Attacks

The web browser has long been a critical entry point for cyberattacks, but recent trends have dramatically increased the risk. According to cside’s recently released ‘Client-Side Attack Report Q2 2025’, over 72,000 websites have been compromised, with attackers increasingly exploiting JavaScript-based delivery mechanisms and vulnerabilities in third-party web scripts. This shift is driven by the fact that traditional server-side security measures often fail to detect and prevent attacks that originate and execute within the user's browser.

“For too long, security teams have focused primarily on protecting the server, assuming that anything reaching the user’s browser is safe,” explains one security analyst. “But that assumption is increasingly invalid. Attackers are adept at bypassing server-side defenses and exploiting vulnerabilities in client-side code.”

The consequences of these attacks can be severe, ranging from data breaches and financial losses to reputational damage and compliance violations. A recent industry report indicated that 95% of organizations have experienced browser-originated attacks in the past year, with the financial sector being particularly vulnerable.

cside's Approach to Browser Security

cside addresses this growing threat by providing real-time visibility and control over client-side activity. The company's platform monitors all JavaScript code executing in the browser, identifying and blocking malicious behavior before it can cause harm. Unlike traditional security solutions that rely on signatures or blacklists, cside uses a hybrid proxy model and AI-powered engines to de-obfuscate JavaScript and flag suspicious activity, even if it’s never been seen before.

“We’re essentially building a firewall for the browser,” explains a cside spokesperson. “We intercept all client-side requests, analyze them for malicious intent, and then either allow or block them. This gives our customers a much higher level of protection against browser-based attacks.”

The company's platform also provides detailed insights into the behavior of third-party scripts, helping customers identify and mitigate supply chain risks. This is particularly important given the increasing reliance on third-party code for web applications. A single compromised script can expose a website to a wide range of threats, often going undetected for weeks or even months. cside’s solution helps organizations identify rogue scripts, block unwanted data transfer, and ensure compliance with evolving regulations like PCI DSS 4.0.1.

Market Validation and Competitive Landscape

The recent awards secured by cside – from Cyber Defense Awards, SourceForge, and CRN – validate the company’s innovative approach and growing traction in the market. These accolades highlight the increasing recognition of client-side security as a critical component of a comprehensive cybersecurity strategy. The CRN ‘Stellar Startup’ award, in particular, underscores cside’s potential for long-term growth and disruption in the security industry.

cside is not alone in this emerging market. Established security vendors like Imperva and Cloudflare offer client-side protection features as part of their broader web application firewalls. However, dedicated client-side security platforms like Jscrambler, Reflectiz, and Source Defense are also gaining ground. cside differentiates itself through its focus on real-time threat detection, AI-powered analysis, and detailed visibility into third-party script behavior. The company’s $7.69 million seed funding round demonstrates investor confidence in its technology and potential for growth.

“There's a lot of buzz around client-side security right now, and for good reason,” says one industry observer. “Organizations are realizing that traditional security measures are no longer enough. They need a solution that can protect them from the evolving threats that are targeting the browser.”

The increasing sophistication of browser-based attacks, combined with the growing regulatory pressure to protect sensitive data, is driving demand for client-side security solutions like cside. As more organizations adopt these technologies, the market is poised for significant growth in the coming years.