Zscaler is “Highly Effective & Reliable” in NSS Labs SSE Threat Protection Test

As threat actors increasingly leverage AI to enhance the speed, scale, and sophistication of their attacks, the methods used to validate cybersecurity controls must evolve at an even faster pace. Point-in-time, manual testing, while once the standard, is no longer sufficient to measure a platform’s resilience against a continuous barrage of automated and evasive threats.

This is why Zscaler consistently invests in product improvement driven by independent validation to prove our platform stays ahead of Advanced Persistent Threats. We are thrilled to announce that Zscaler Zero Trust Exchange^TM has been considered a Highly Effective & Reliable cloud-delivered security platform in the Q2 2026 Security Service Edge (SSE) Threat Protection test from NSS Labs. Zscaler’s performance in rigorous third-party testing has set the industry benchmark, once again proving its dominance against the most advanced, AI-driven testing methodology in the industry.

Sustaining its leadership under this new wave of testing, the Zscaler Zero Trust Exchange™ platform delivered an overall security efficacy of 98.85%. This highly effective score was composed of exceptional results across the most critical protection categories, including a 100% resistance rate against sophisticated evasion techniques, 98.65% malware block rate, a 99.05% exploit block rate, and a false positive accuracy of 99.63%. These results provide unequivocal proof that Zscaler delivers superior protection to keep organizations secure.

Test Methodology

The goal of the NSS Labs SSE Threat Protection test was to assess the real-world capabilities and performance of Security Service Edge (SSE) platforms using a substantially updated SSE Threat Protection Methodology. The methodology is designed to measure how effectively a security solution protects users from threats, regardless of their location. The core areas of assessment included:

• Threat Protection: Evaluating the platform’s ability to effectively block exploits and malware from reaching end-users.
• Resistance to Evasion: Measuring the platform's resilience against techniques used by attackers to disguise their payloads and circumvent security controls.

Key Findings: A Deeper Look at the Results

Zscaler's Highly Effective rating is the result of consistent test results across all major categories. Let’s explore the key findings in more detail.

98.65% Malware Block Rate

The Result: Tested against 4,873 unique malware samples, Zscaler achieved a 98.65% block rate, stopping everything from common ransomware strains to advanced, polymorphic threats.

The Business impact: A single successful malware infection can lead to devastating consequences, including crippled operations, stolen data, significant financial loss, and lasting brand damage. An effective security platform must not only block known malware but also identify and stop novel, zero-day threats before they can execute.

How Zscaler Delivers: This highly effective protection is the result of a powerful defense-in-depth strategy. It starts with full TLS/SSL inspection and is amplified by a suite of AI-powered malware detection engines. Our Advanced Cloud Sandbox quarantines and analyzes unknown threats inline, while the "cloud effect" – derived from processing over 500 billion daily transactions and blocking billions of threats – ensures that a threat seen once is blocked for every other customer instantly.

99.05% Exploit Block Rate

The Result: Zscaler blocked 99.05% of the 317 unique exploits tested, which targeted a wide range of applications, protocols, and operating systems.

The Business impact: Exploits are the weapons threat actors use to gain an initial foothold, bypass security controls, and move laterally within a network. Preventing the exploit is the most effective way to stop an attack chain before it can even begin. This is especially critical for defending against zero-day attacks that target newly discovered vulnerabilities.

How Zscaler Delivers: Zscaler's zero trust architecture inherently reduces the attack surface, making it harder for exploits to find a target. For traffic passing through the platform, our inline Intrusion Prevention System (IPS) and Advanced Threat Protection capabilities work in concert to identify and block exploit attempts in real time, protecting users and systems from compromise.

100% Evasions Resistance

The Result: NSS Labs tested Zscaler against 583 different evasion techniques, and the Zero Trust Exchange demonstrated a 100% success rate in identifying and blocking the underlying threat.

The Business impact: Advanced attackers rarely use off-the-shelf malware; they use obfuscation, compression, and other evasion techniques to sneak their payloads past security defenses. A security control that cannot see through these disguises offers a false sense of security. Resilience to evasion is a key differentiator between basic security and a truly advanced threat protection platform.

How Zscaler Delivers: Zscaler’s proxy-based architecture reconstructs all traffic before inspection, allowing our multiple security engines to see and decode even the most complex, layered evasion attempts. We don't just detect that an evasion is being used; we neutralize the evasion and block the malicious payload it was designed to hide.

99.63% False Positive Accuracy

The Result: While aggressively blocking threats, Zscaler maintained an exceptional 99.63% accuracy rate, correctly identifying legitimate files and traffic.

The Business impact: False positives are more than just an annoyance; they erode trust in the security platform and create significant operational drag. When security teams are buried in false alerts, they waste valuable time and may be forced to disable critical security features, inadvertently opening the door to real threats. High accuracy is essential for both strong security and efficient operations.

How Zscaler Delivers: The massive dataset flowing through the Zscaler cloud is our greatest strength. We use advanced AI and machine learning models, trained on trillions of signals from billions of daily transactions, to precisely differentiate between malicious and benign traffic. This allows us to maintain the highest level of threat protection without disrupting legitimate business activities.

What This Means for Your Enterprise

Thriving in the age of AI-driven threats requires investing in security that has been validated by an equally advanced testing methodology. Zscaler has achieved top-tier results in independent testing, and this year's Highly Effective rating against a highly advanced evaluation is our most significant accomplishment yet.

These results are not just numbers on a page; they represent peace of mind. They affirm that with Zscaler, your organization is protected by a platform that has been battle-tested against the most sophisticated threats and the most rigorous validation standard in the world. As you navigate the complexities of digital transformation and secure your adoption of AI, Zscaler’s consistent, proven leadership makes it the clear and trusted choice to safeguard your users, data, and applications.

Get the Full Report

We invite you to download the full NSS Labs SSE Threat Protection report for a deeper analysis of Zscaler’s detailed performance, and what it means for your security strategy.

[Download the Full Report Here]