Stellar Cyber Open XDR

Stellar Cyber has built its SIEM specifically around the multi-tenant reality that MSPs and MSSPs live in, rather than retrofitting a single-tenant platform to awkwardly serve multiple clients. The architecture aggregates security telemetry from over 400 third-party sources without requiring a proprietary sensor, making it genuinely vendor-agnostic in a way that suits service providers managing diverse client environments with different existing tools. The 4.7 G2 rating from 43 reviews reflects real satisfaction, particularly from MSP customers who cite operational efficiency managing multiple tenants from a single console as the primary reason they chose Stellar Cyber over adapting an enterprise SIEM.

The honest limitation is scale and formal validation. There is no Gartner Magic Quadrant presence, and while the aggregated detection content is broad, it is less deeply curated than Splunk's mature ESCU library built over fifteen years.

The verdict: Stellar Cyber is right for MSPs and MSSPs needing genuine multi-tenant SIEM architecture to manage multiple client environments efficiently. Single-tenant enterprises should evaluate Rapid7 InsightIDR or Microsoft Sentinel instead.

Last reviewed: September 2026

Strongest: Log source coverage

Watch out for: Detection content

Best for

Managed service providers and MSSPs managing multiple client security environments who need genuine multi-tenant SIEM architecture rather than a single-tenant platform adapted for multiple clients.

Not suitable for: Single-tenant enterprises without multi-tenant requirements, or organisations needing Gartner Magic Quadrant validated vendors for procurement.