The Best CASB Vendors in 2026: An Independent Assessment

Shadow IT is not a policy failure. It is a visibility failure. The average enterprise IT team knows about roughly 30 to 40 SaaS applications in active use. The actual number, once measured, is typically 3 to 5 times higher. Employees sign up for tools with a company email address, connect them to company data, and IT finds out during an incident investigation, not before one.

Cloud Access Security Broker platforms exist to close that gap. This guide covers what CASB actually does, which vendors are worth evaluating in 2026, and how CASB fits alongside the other cloud security tools most organisations are already running.

What CASB actually does

A CASB sits between your users and the cloud applications they access, giving security teams visibility and control that neither the identity provider nor the applications themselves provide on their own.

Shadow IT discovery identifies every cloud application employees are using, including ones IT never approved or sanctioned. This is usually the first capability that justifies a CASB purchase, because the discovery report is consistently the moment security teams realise the scale of the problem.

Data loss prevention for cloud apps inspects data moving into and out of sanctioned SaaS applications, blocking or flagging sensitive data uploads that violate policy, such as customer records being uploaded to a personal Google Drive account.

Access control and adaptive policy applies conditional rules to cloud app access based on device, location, and risk signals, similar to conditional access in an identity provider but extended to the application layer rather than just the login event.

Threat protection detects anomalous activity within sanctioned cloud applications, such as unusual download volumes that might indicate data exfiltration or account compromise.

Compliance reporting maps cloud application usage against regulatory requirements, showing which applications handle regulated data and whether they meet the compliance obligations that apply to that data.

CASB versus the tools you already own

The most common question we hear from buyers evaluating CASB is whether it duplicates capabilities they already have elsewhere.

CASB versus your identity provider. Okta and Microsoft Entra control who can log into which application. CASB controls what happens after login, inspecting the data flowing through the session. These are complementary controls, not competing ones.

CASB versus your firewall or SWG. A secure web gateway controls which websites and applications users can reach on the network. CASB provides deep visibility into what happens inside sanctioned cloud applications specifically, which a network layer tool cannot see.

CASB versus DLP. Standalone DLP tools typically protect email and endpoint data movement. CASB extends DLP policy specifically into cloud application data flows, which is often a gap in traditional DLP deployments that predate widespread SaaS adoption.

The market trend in 2026 is convergence. Most CASB capability now ships as part of a broader SSE or SASE platform rather than as a standalone product, which changes how buyers should evaluate vendors.

The 10 CASB vendors we assessed

Netskope One CASB

Combined score: 4.6

Netskope has the deepest real time SaaS application inspection in the CASB category, covering more than 50,000 cloud services with granular visibility into application activity rather than just DNS level access logging. The furthest Completeness of Vision position in Gartner's SSE Magic Quadrant reflects a genuinely differentiated architecture built around the NewEdge network for low latency inline inspection.

The unified DLP policy engine applying consistently across CASB, ZTNA, and web traffic means organisations get one policy framework rather than separate rules for each channel. The premium pricing and enterprise minimum seat requirements put it out of reach for SMB and mid-market buyers.

What to ask Netskope: What does the deployment timeline look like for our estimated SaaS application count. How does the shadow IT discovery report get delivered and how often is it refreshed. What does pricing look like at our user count including the DLP module.

Microsoft Defender for Cloud Apps

Combined score: 4.5

For Microsoft 365 E5 customers this is the CASB with the lowest deployment friction available. Zero additional licensing cost, native integration with Conditional Access, Entra ID, and Purview, and coverage of 26,000 plus cloud applications make it the obvious first evaluation for Microsoft first organisations.

The honest limitation is that non Microsoft SaaS app visibility depth requires additional API connector configuration, and inline inspection of non Microsoft traffic is less mature than dedicated CASB platforms.

What to ask Microsoft: Which specific cloud applications in our environment have native API connectors versus requiring custom configuration. What does shadow IT discovery cost beyond the base Defender for Cloud Apps license.

Zscaler CASB (part of ZIA)

Combined score: 4.5

Zscaler delivers CASB as an inline capability within the Zero Trust Exchange, inspecting every byte of SaaS traffic at one of 150 plus global points of presence before it reaches its destination. The Leader position in Gartner SSE with the highest Ability to Execute reflects proven enterprise scale deployment.

CASB exists as a module within the broader ZIA platform rather than a standalone purchase, meaning buyers adopt the full Zscaler architecture to access it.

Palo Alto Prisma SaaS

Combined score: 4.3

Prisma SaaS brings the deepest inline DLP inspection of any CASB, built on Palo Alto's NGFW content inspection heritage. Organisations already running Palo Alto NGFW and Cortex XDR get a unified policy context across network, endpoint, and cloud application access that reduces the number of separate security policies to manage.

Deployment complexity and admin learning curve are consistently the highest in the CASB category, requiring dedicated Palo Alto expertise.

Skyhigh Security CASB

Combined score: 4.1

Skyhigh carries the McAfee MVISION Cloud heritage, one of the original enterprise CASB platforms, with deep API based SaaS visibility across 40,000 plus cloud services. For organisations with existing McAfee or Skyhigh investment, continuity without platform migration is the primary argument for staying.

Symphony Technology Group ownership has slowed the innovation pace that defined the McAfee MVISION Cloud years, and Gartner positions Skyhigh as a Niche Player reflecting this gap.

Forcepoint ONE CASB

Combined score: 4.0

Forcepoint brings the Bitglass reverse proxy heritage, one of the original agentless CASB approaches providing visibility into unmanaged BYOD devices without requiring agent installation. The native integration with Forcepoint DLP creates the strongest DLP CASB combination in the category for existing Forcepoint customers.

Francisco Partners PE ownership raises the same long term investment questions common across the private equity owned segment of the security market.

Cato Networks CASB

Combined score: 4.2

Cato delivers CASB as a native capability within the most genuinely converged SASE platform in the market, sharing a single policy engine with SD-WAN, ZTNA, NGFW, and SWG. For mid-market enterprises replacing MPLS and VPN with a single vendor SASE platform, this architectural simplicity is a significant advantage over bolting CASB onto existing infrastructure.

CASB feature depth for granular SaaS application control is less than dedicated CASB specialists.

Cisco Umbrella CASB

Combined score: 4.0

Umbrella delivers CASB through DNS based inspection, making it the simplest CASB deployment in the category. Point DNS at Umbrella and cloud application access is logged and controlled within minutes, with Talos threat intelligence applied to cloud traffic.

The DNS based approach has inherent depth limitations. Granular SaaS application data inspection for content level DLP requires inline proxy inspection that DNS cannot provide, and Cisco was dropped from Gartner's SSE Magic Quadrant Leaders in 2024.

Lookout CASB

Combined score: 3.9

Lookout brings the CipherCloud heritage of cloud data encryption and tokenisation, a capability that most CASB vendors cannot match, allowing sensitive data to be encrypted before it reaches the SaaS application so the cloud vendor never sees plaintext.

The Fortra acquisition has slowed platform development, and the 2023 GoAnywhere MFT zero day affecting a separate Fortra product line raises parent company security hygiene questions worth investigating.

iboss CASB

Combined score: 3.9

iboss is the most accessible enterprise CASB for SMB, education, and US government buyers, with FedRAMP Moderate authorisation and broad OS coverage including Chromebook and Linux that no other CASB vendor matches.

SaaS data inspection depth and advanced DLP sophistication are less than Netskope or Zscaler.

How to choose a CASB

Start with your biggest risk. If shadow IT discovery is the primary driver, prioritise vendors with the broadest application catalog and the richest discovery reporting. Netskope and Skyhigh lead here. If DLP for sanctioned cloud apps is the driver, prioritise vendors with the deepest inline inspection. Palo Alto and Zscaler lead here.

Match architecture to your existing stack. If you are already committed to Zscaler, Palo Alto, or Cato for SASE, adopting their native CASB module is almost always more efficient than bolting on a separate CASB vendor.

Consider deployment friction honestly. DNS based CASB like Cisco Umbrella deploys fastest but with the least depth. Inline proxy CASB like Netskope or Zscaler delivers the deepest visibility but requires more configuration.

CASB and Essential Eight

CASB is not explicitly named in the Essential Eight strategies, but it directly supports Strategy 7 (restrict administrative privileges) and Strategy 8 (application control) as they extend to cloud applications, which the original Essential Eight framework predates in its focus on on-premises infrastructure.

For organisations with significant SaaS adoption, CASB is increasingly treated as a practical necessity for demonstrating comprehensive application control that satisfies auditor expectations, even where it is not a named requirement.

Questions every CASB buyer should ask

What percentage of our actual cloud application usage will this platform discover in the first 30 days.

How does the DLP policy engine handle false positives and what tuning is required before it is usable in production.

What does the deployment look like for BYOD and unmanaged devices specifically.

How does this integrate with our existing SIEM for alert correlation.

What is the total cost including any required DLP or threat protection add-on modules.

Our recommendation by buyer type

Large cloud first enterprise: Netskope for the deepest SaaS visibility and unified policy engine.

Microsoft 365 E5 organisation: Microsoft Defender for Cloud Apps for zero additional licensing cost.

Existing Zscaler or Palo Alto customer: Adopt the native CASB module rather than a separate vendor. See Zscaler CASB and Palo Alto Prisma SaaS.

Mid-market replacing MPLS and VPN: Cato Networks for the most converged SASE architecture.

SMB or government with FedRAMP requirement: iboss for accessible pricing and broad OS support.

How we scored these vendors

Every vendor on Comparisec is scored independently using Gartner Peer Insights, G2, and PeerSpot data weighted by review volume. No vendor has paid to appear on this site or influence their score.

Last reviewed: August 2026. Vendor scores and market positions are updated quarterly.

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