The best attack surface management platforms for most buyers in 2026 are Censys, for external discovery built on its own scans of the entire internet across all 65,000 ports; CyCognito, for black-box discovery paired with active testing that confirms which exposures are exploitable; and Palo Alto Networks Cortex Xpanse, for internet-scale scanning with automated response playbooks. This guide to the Top Attack Surface Management Platforms In 2026 covers seven more platforms, including cyber asset attack surface management tools that map what sits inside the network.
This list is for security and IT teams that need an accurate, always-current picture of what they expose, whether that is forgotten subdomains and shadow cloud on the internet or unmanaged devices on the internal network. We included two types of platform: external attack surface management (EASM), which discovers internet-facing assets from the outside, and cyber asset attack surface management (CAASM), which builds an inventory from your existing tools and network scans. We compared discovery method, validation, prioritization and integrations using the vendors’ own product pages and press releases, and checked product names after the 2025 and 2026 acquisitions. New to the category? Start with what is attack surface management.
Attack Surface Management Platforms At A Glance
Company
Headquarters
Best For
ASM Type
Censys
Ann Arbor, Michigan, USA
Internet-wide visibility and threat hunting
EASM
CyCognito
Palo Alto, California, USA and Tel Aviv, Israel
Discovery plus active exploitability testing
EASM with exposure validation
Palo Alto Networks (Cortex Xpanse)
Santa Clara, California, USA
Large enterprises wanting automated response
EASM
Microsoft (Defender EASM)
Redmond, Washington, USA
Azure and Microsoft security customers
EASM
Tenable (Tenable One Attack Surface Management)
Columbia, Maryland, USA
Exposure management in one platform
EASM
Rapid7 (Surface Command)
Boston, Massachusetts, USA
Combining internal and external views
EASM and CAASM
IONIX
Tel Aviv, Israel and Kirkland, Washington, USA
Digital supply chain exposure
EASM with exposure validation
Axonius
New York, New York, USA
Unified asset inventory from existing tools
CAASM
runZero
Part of Dragos (Hanover, Maryland, USA)
IT, OT and IoT asset discovery
CAASM and exposure management
Detectify
Stockholm, Sweden
Application-heavy external surfaces
EASM with payload-based testing
Best Attack Surface Management Platforms In 2026
1. Censys — EASM Built On Its Own Map Of The Internet
Censys, based in Ann Arbor and led by founder and CEO Zakir Durumeric, runs its own first-party scans of the internet. Its attack surface management product uses that data to find your internet-facing assets, including services running on nonstandard ports, hosts with self-signed certificates and hosts on residential networks. Censys says it maps the internet across all 65,000 ports.
Censys ASM alerts on changes in hosts, ports, certificates and services, and it scores vulnerabilities with EPSS, the CISA KEV catalog and other risk signals. When Censys ARC, its research team, flags a new critical exposure or active exploitation, customers can quickly see whether they have affected assets. Integrations with ticketing, vulnerability management and security tools route remediation work, and executive and audit views track exposure trends.
The same data powers Censys Search and its threat hunting products, so security operations and threat intelligence teams can share one source. Censys says organizations representing more than half of the Fortune 500 use it, and it raised 70 million dollars in strategic funding in 2026.
Best for: Security teams that want the most complete external view, plus threat hunting on the same data.
2. CyCognito — Black-Box Discovery With Active Exposure Testing
CyCognito was founded in 2017 by Rob Gurzeev and Dima Potekhin and has offices in Palo Alto and Tel Aviv. It now calls its product a preemptive exposure management platform. Discovery takes an attacker’s view, using deep black-box reconnaissance to map assets you may not know about, then attributes each asset to an owner, business function and data type and fingerprints its technology stack.
Testing is where CyCognito differs from discovery-only tools. Its adversarial exposure validation sends real payloads to exposed assets to confirm exploitability, using more than 100,000 testing modules across 30-plus threat categories that span web, API, cloud and network surfaces. It also flags non-CVE issues such as misconfigurations, default credentials and exposed data. A newer Continuous AI Pentesting offering uses AI agents to chain exposures across apps, APIs, cloud and AI services.
Prioritization weighs asset context, threat intelligence, discoverability and attractiveness to attackers. CyCognito was named a Leader and Outperformer in the 2026 GigaOm Radar for Attack Surface Management, and it integrates with Palo Alto Networks, Tenable, Wiz, CrowdStrike, ServiceNow and Splunk.
Best for: Large, decentralized organizations that need unknown assets found and their exploitability confirmed in one platform.
3. Palo Alto Networks — Cortex Xpanse Active ASM With Automated Response
Cortex Xpanse, from Santa Clara-based Palo Alto Networks, is an agentless SaaS platform that discovers, learns about and responds to exposures from outside the corporate network. Its scale is the headline: Palo Alto Networks says Xpanse scans more than 500 billion ports a day and every IPv4 address several times daily.
Xpanse uses supervised machine learning to map assets to your organization and prioritize remediation. The Active Response add-on brings built-in automated playbooks that can reduce exposure directly and support alert investigation, which is useful when the volume of findings outpaces the team. Listed use cases include finding shadow cloud, responding to zero-days, M&A due diligence and lowering cyber insurance risk.
Xpanse sits within the Cortex security operations portfolio, so it is a natural fit for existing Palo Alto Networks customers. It was named a Leader and Outperformer in the GigaOm ASM Radar.
Best for: Large enterprises on Palo Alto Networks platforms that want ASM findings to trigger automated remediation.
4. Microsoft — Defender EASM For Microsoft-Centric Security Teams
Microsoft Defender External Attack Surface Management maps an organization’s internet-exposed presence, including shadow IT and assets created through everyday growth. Discovery starts from seeds, such as known domains and IP blocks, and follows observed connections recursively to find related infrastructure, including domains, hosts, IP ranges, ASNs, email contacts and Whois organizations.
Assets are indexed into a dynamic inventory marked recent or historic, including web applications and third-party dependencies. Dashboards highlight vulnerabilities, compliance issues and hygiene problems such as open ports, SSL issues, OWASP Top 10 findings and CVE exposure, with a Copilot insights panel. Teams can filter the inventory, for example to find assets tied to deprecating infrastructure or newly found cloud resources, and customer data stays in the region you select.
Defender EASM runs as an Azure resource, which makes it straightforward to trial for organizations already standardized on Microsoft security and Sentinel. A free trial is available.
Best for: Organizations already invested in Azure and Microsoft Defender that want external discovery without adding a new vendor.
5. Tenable — Tenable One Attack Surface Management
Tenable, headquartered in Columbia, Maryland, sells its EASM as Tenable One Attack Surface Management, part of its exposure management platform. It continuously monitors the internet for assets tied to your organization, using an attack surface map that Tenable says covers more than five billion assets, and notifies you of changes.
Each asset carries more than 200 metadata fields, plus filters and tags, to help prioritize. Teams can launch scans of unassessed assets straight from the product, which is a natural fit for existing Tenable vulnerability management customers. Use cases go beyond security to compliance, brand protection, M&A and legal review.
The key benefit is consolidation. External asset and exposure data flow into Tenable One alongside vulnerability, cloud and identity data, with built-in cyber asset management, so teams do not need a separate inventory tool.
Best for: Tenable customers who want external discovery in the same exposure management platform as their vulnerability data.
6. Rapid7 — Surface Command For Internal And External Attack Surfaces
Rapid7’s Surface Command combines external attack surface management with cyber asset attack surface management in one product on the Command Platform. On the external side, it starts from seeds, registered domains and public IP ranges, to uncover subdomains, network services and TLS certificates, then validates exposures from an attacker’s view.
On the internal side, connectors pull data from vulnerability scanners, endpoint protection, cloud services and identity providers, and Surface Command correlates records into unified assets and identities, including service accounts and shared mailboxes. That makes it easier to spot coverage gaps, such as servers with no EDR agent. Teams query the graph with Cypher or a visual builder, build dashboards and run automated workflows for response.
Rapid7 provides connectors for most major tools and supports custom ones, and orchestrators can reach sources the cloud platform cannot.
Best for: Teams that want one view of both internet-facing exposures and internal asset coverage gaps.
7. IONIX — EASM That Follows Your Digital Supply Chain
IONIX, founded in 2016 as Cyberpion and rebranded in 2023, has offices in Tel Aviv and Kirkland, Washington. It was an early external attack surface management vendor, and its focus is the connected assets and digital dependencies around your organization, including vendor-managed infrastructure, not just the assets you own directly.
Its Exposure Validation module runs non-disruptive active exploitability testing, and findings are prioritized by severity, exploitability, blast radius and asset importance. Other modules include Active Protection, WAF posture management and Live Exposure Defense, which IONIX says aims to take an exposure from CVE to mitigated within 12 hours. IONIX claims it discovers 30% to 50% more assets than alternatives, a figure worth testing in a trial.
Customers include E.ON, Infosys, BlackRock and Warner Music Group, and IONIX offers a free attack surface scan.
Best for: Enterprises worried about exposure through third-party and supply chain infrastructure.
8. Axonius — CAASM Asset Intelligence From Existing Tools
New York-based Axonius, founded in 2017, is a leading CAASM vendor. Rather than scanning, the Axonius Asset Cloud connects to the tools you already run, through more than 1,400 adapters, and builds a unified asset inventory from them. The company reported annual recurring revenue above 200 million dollars in 2026.
That unified model makes it easy to find coverage gaps, such as devices missing an endpoint agent, misconfigurations and unmanaged assets, and then act on them through automated workflows. Use cases include asset discovery, CMDB data quality, exposure management and incident response. Axonius cites a Forrester Total Economic Impact study reporting about 80% less time spent on asset inventory.
Axonius was named a Strong Performer in The Forrester Wave for Proactive Security Platforms in Q3 2026.
Best for: IT and security teams with many tools that need one trustworthy inventory before they can manage exposure.
9. runZero — Agentless Discovery Across IT, OT And IoT
runZero was founded in 2018 by HD Moore, the creator of Metasploit, and was acquired by OT security firm Dragos in September 2026 along with NetRise. It continues to serve existing customers while it is integrated into the Dragos Platform.
runZero combines active scanning, passive discovery, API integrations and fingerprinting, profiling each asset against nearly 1,000 attributes without agents or credentials. That makes it strong at finding devices other tools cannot see, including OT, IoT, mobile and remote assets. It links internal topology with external exposures to map likely attack paths, and version 5.1 adds natural language search and AI-built reports.
A free Community Edition covers environments with fewer than 100 assets.
Best for: Organizations with mixed IT and OT estates, such as manufacturers and universities, that need accurate discovery of unmanaged devices.
10. Detectify — Surface Monitoring Powered By Ethical Hacker Research
Stockholm-based Detectify was founded in 2013 by ethical hackers and is used by more than 2,100 organizations. Its Surface Monitoring product discovers and maps domains, subdomains, IPs, technologies, ports and protocols, then runs payload-based tests against what it finds rather than only matching versions to CVEs.
Those tests come from a community of more than 400 ethical hackers who submit research that Detectify turns into modules. The company says 99% of the vulnerabilities it finds have no CVE, which reflects its focus on real-world application flaws. Surface Monitoring pairs with Application Scanning, API scanning of REST and GraphQL endpoints, internal scanning and PCI ASV scanning.
Best for: Companies whose external surface is mostly web applications and APIs and who want testing beyond CVE matching.
How To Choose An Attack Surface Management Platform
Do You Need EASM, CAASM Or Both?
EASM tools such as Censys, CyCognito, Xpanse and Defender EASM find what is exposed on the internet. CAASM tools such as Axonius and runZero build an inventory inside your environment. Rapid7 Surface Command does both. Many organizations start with EASM and add CAASM once the external picture is under control.
How Does It Discover Assets?
Seed-based discovery starts from domains and IPs you provide, while black-box discovery starts with little more than your name. Ask each vendor to run discovery on your organization and compare results against your own inventory.
If you already run Tenable, Rapid7, Microsoft or Palo Alto Networks, their ASM products will slot into existing workflows. Independent vendors often discover more but add another console, so check ticketing and SIEM integrations.
Frequently Asked Questions
What Is Attack Surface Management?
Attack surface management is the continuous discovery, inventory, prioritization and monitoring of the assets an attacker could target, from internet-facing domains and cloud services to internal devices. Read what is attack surface management for a full explanation.
What Is The Difference Between EASM And CAASM?
EASM looks from the outside in, discovering internet-exposed assets the way an attacker would. CAASM looks from the inside out, combining data from your existing IT and security tools into one inventory.
Does Attack Surface Management Replace Penetration Testing?
Censys is the strongest pick for raw external visibility, CyCognito suits organizations that want discovery and exploitability testing together, and Cortex Xpanse fits large enterprises that want automated response. Microsoft Defender EASM, Tenable One Attack Surface Management, Rapid7 Surface Command, IONIX, Axonius, runZero and Detectify each serve a specific need, from platform consolidation to OT discovery and application-focused testing.
