TL;DR: Legacy SIEM schemas create lock-in, slow correlation, and make AI-driven detection harder to operationalise. DataBahn argues that the Open Cybersecurity Schema Framework, or OCSF, gives security teams a vendor-neutral model for telemetry flow, lakehouse architectures, and compliance-driven correlation as NIS2 and DORA deadlines tighten. The architectural shift is no longer optional when data fragmentation becomes a governance problem.
At a glance
What this is: OCSF is presented as the vendor-neutral schema that can standardize security telemetry across SIEMs, lakes, and AI-driven analytics.
Why it matters: It matters because identity, cloud, endpoint, and network telemetry only becomes governable when security teams can normalize it consistently enough for detection, compliance, and investigation.
By the numbers:
- The project has grown from 17 founding companies to over 900 contributors and 200 participating organizations.
Context
Security telemetry becomes hard to govern when the same action, user, or asset is described differently by every tool in the stack. That is the central problem OCSF is designed to address: fragmented event data that slows detection, complicates compliance, and makes AI harder to apply across heterogeneous environments.
The identity bridge here is real. When authentication events, cloud activity, and endpoint telemetry do not share a common structure, IAM and SOC teams cannot reliably correlate access, privilege, and follow-on activity across systems. OCSF matters because it turns field-level consistency into an operating assumption rather than a manual cleanup task.
DataBahn frames OCSF as a response to a market that has moved beyond single-platform SIEM assumptions. The article’s core claim is that normalization is now a governance requirement, not just a parsing convenience, and that view is increasingly typical across modern security architectures.
Key questions
Q: How should security teams normalise telemetry for SIEM and lakehouse architectures?
A: Security teams should normalise telemetry as close to collection as practical, using a shared schema so routing, retention, and detection all see the same event structure. The goal is not cosmetic consistency. It is preserving meaning across identity, cloud, endpoint, and network sources so analytics can operate without constant translation overhead.
Q: Why does schema fragmentation make AI-driven detection harder?
A: AI systems depend on consistent semantics. When authentication events, network logs, and cloud activity use different field names or event models, the model has to infer meaning that should already be encoded. That reduces correlation quality, weakens retraining efficiency, and makes cross-source reasoning much less reliable.
Q: What breaks when proprietary SIEM schemas become the default data model?
A: The main failure is portability. Detection rules, dashboards, parsers, and compliance queries become tied to one vendor’s data model, so migration or dual-routing means reworking the whole pipeline. That creates lock-in and raises the cost of modernising storage or analytics.
Q: Should teams prioritise schema standardisation before expanding AI use in the SOC?
A: Yes, if the current telemetry estate is still fragmented. AI detection built on inconsistent inputs will simply automate ambiguity. Standardising the schema first gives the SOC a shared evidence layer, which is the prerequisite for trustworthy triage, correlation, and downstream automation.
Technical breakdown
Why proprietary normalization breaks cross-platform detection
Vendor-specific schemas improve consistency inside one platform, but they create friction everywhere else. When telemetry uses different field names and event structures across SIEM, cloud, identity, and endpoint sources, detection engineers must translate before they can correlate. That translation burden becomes a hidden dependency in the analytics layer. OCSF addresses this by defining a shared event model with categories, classes, and attributes that preserve meaning across sources. The point is not just cleaner logs. It is semantic portability, so correlation logic can survive platform change, storage decoupling, and mixed-vendor telemetry.
Practical implication: Treat schema normalisation as a control-plane issue, not a parser maintenance task.
How OCSF supports lakehouse security architectures
Lakehouse architectures separate storage from analytics, which means telemetry can no longer depend on one SIEM’s internal data model. Raw events land in lower-cost storage, while analytics engines query what they need on demand. That only works if the event structure remains consistent across tiers. OCSF provides the common schema that lets hot and cold data stay queryable without re-mapping every source for every destination. In practice, this changes normalisation from an ingestion-side convenience into a governance layer that determines how portable the data remains once it leaves the source system.
Practical implication: Normalise telemetry before or during pipeline transit so storage tiering does not break downstream analysis.
Why AI detection depends on semantic consistency
AI-driven detection fails when the model has to infer meaning from incompatible field names across sources. An authentication failure, a network anomaly, and a cloud control-plane event can only be reasoned over together if the event schema carries consistent semantics. OCSF gives AI systems that common structure. It does not make models intelligent by itself, but it removes one of the main reasons models underperform in SOC environments: inconsistent input data. The operational effect is that detection, triage, and correlation can increasingly be built on structured context instead of custom translation logic.
Practical implication: Align AI detection pipelines to a shared schema before investing in model-led correlation use cases.
Threat narrative
Attacker objective: The practical objective is to hide or extend malicious activity inside a telemetry environment that cannot correlate it fast enough.
- Entry happens through telemetry fragmentation, where every source emits security events in a different format and analysts lose time reconciling them.
- Credentialed and privilege-related activity becomes harder to correlate when identity, cloud, and endpoint logs do not share a common field model.
- The impact is operational rather than explosive: slower detection, weaker cross-system correlation, and a governance layer that cannot keep pace with modern architectures.
Breaches seen in the wild
- Microsoft Midnight Blizzard breach: Midnight Blizzard (APT29) exploited legacy test account without MFA to breach Microsoft.
Read and download The State of NHI & AI Agent Breach Report 2026, covering 200+ breaches impacting Non-Human Identities including AI Agents.
NHI Mgmt Group analysis
OCSF is becoming the control plane for security data, not just a log format. The article is right to frame schema as governance infrastructure rather than an implementation detail. Once telemetry moves into lakehouse and AI-driven architectures, the schema determines whether correlation rules, compliance queries, and investigation workflows remain portable. Practitioners should stop treating normalisation as a backend utility and treat it as part of the operating model.
Data fragmentation has become an identity governance problem as much as a SOC problem. Authentication, privilege, and session data lose value when each platform describes them differently. That breaks the ability to reconstruct who or what acted, when it acted, and across which systems. The result is not just slower detection but weaker accountability, especially where IAM, cloud, and endpoint evidence must line up for audit or incident review.
AI-ready security data depends on semantic consistency before the model ever sees the event. If the SOC feeds inconsistent telemetry into AI tooling, the model inherits ambiguity instead of reducing it. OCSF matters because it pushes structure upstream, where the data is still governable. The practitioner lesson is simple: AI detection initiatives should be judged on input quality and schema discipline, not just on model selection.
Legacy SIEM lock-in is now an architectural risk rather than a procurement inconvenience. Proprietary schemas create switching costs, but they also shape how teams think about detection, retention, and storage. Once a vendor’s schema defines the pipeline, migration becomes a re-engineering exercise. Security leaders should expect data portability to become a board-level issue whenever logging strategy, lakehouse adoption, or AI use cases are on the table.
From our research library:
- Organisations maintain an average of 6 distinct secrets manager instances, creating fragmentation that undermines centralised control, according to the State of Secrets in AppSec.
- Read next: Cloud Workload Identity Guide
What this signals
OCSF adoption will increasingly separate organisations that can govern telemetry as data from those still treating logs as vendor exhaust. The practical difference is portability. Once security data is normalized early, teams can shift storage, analytics, and SIEM strategy without rewriting every detection workflow.
Schema discipline is becoming a prerequisite for AI in the SOC. If the input layer remains inconsistent, machine-assisted triage will continue to produce uneven results. Security leaders should expect data model governance to sit alongside model governance in the next wave of SOC modernisation.
For practitioners
- Map your telemetry estate to a common schema Inventory the main sources that feed detection, retention, and compliance workflows, then identify where proprietary field names block correlation across identity, cloud, endpoint, and network data.
- Move normalisation into the pipeline Apply schema translation before telemetry reaches analytics or storage layers so hot and cold data remain queryable under the same event model.
- Test AI detections against mixed-source telemetry Validate whether current detection content still works when the same event is represented by different vendors, source types, or storage tiers.
- Separate storage strategy from schema strategy Design lakehouse and SIEM routing around a stable event model so routing decisions do not force re-parsing every time a destination changes.
Key takeaways
- OCSF matters because security data fragmentation is no longer just an operational nuisance. It now affects detection quality, investigation speed, and the portability of SOC workflows across vendors and storage tiers.
- The article’s core argument is that a shared schema is becoming necessary for lakehouse security architectures and AI-driven detection. Without that common structure, telemetry remains expensive to move and hard to reason over.
- For practitioners, the implication is to move normalisation upstream and treat schema governance as part of the security architecture, not as a parser cleanup exercise after ingestion.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while NIST CSF 2.0, NIST SP 800-53 Rev 5 and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.DS-01 — Data-at-rest is protected | Normalised telemetry underpins controlled handling of security data across storage and analytics layers. |
| DE.CM-01 — The network and systems are monitored to detect potential cybersecurity events | OCSF improves the consistency of monitored events across tools and sources. | |
| Recommendation — Protect normalized telemetry with data-handling controls that preserve integrity across storage tiers. Standardize monitored event data so detection content works across heterogeneous sources. | ||
| NIST SP 800-53 Rev 5 | AU-3 — Content of Audit Records | The article is fundamentally about making audit records consistent enough to correlate. |
| Recommendation — Define a common audit record structure before routing telemetry into SIEM and lakehouse platforms. | ||
| CIS Controls v8 | CIS-8 — Audit Log Management | The article focuses on log structure, retention, and correlation across modern security stacks. |
| Recommendation — Centralize log governance so telemetry remains usable after format translation and storage changes. | ||
| MITRE ATT&CK | TA0007;TA0008 — Discovery; Lateral Movement | Telemetry normalization improves detection of adversary movement across multiple systems. |
| Recommendation — Map normalized telemetry to discovery and lateral-movement techniques to improve cross-platform hunting. | ||
Key terms
- OCSF: The Open Cybersecurity Schema Framework is an open model for describing security events, findings, and objects in a common structure. It lets vendors map their telemetry into a shared language so downstream analytics, investigations, and automation can work across sources more consistently.
- Telemetry Normalization: Telemetry normalization is the process of turning data from different security tools into a consistent format that can support one policy decision. It is essential when identity, endpoint, and asset systems all feed the same control plane, because conflicting data can otherwise create gaps or overblocking.
- Lakehouse security architecture: A model that separates storage from analytics so raw telemetry can sit in lower-cost data systems while queries and detections run on demand. It depends on structured, portable data because the value of the architecture disappears if event formats are too inconsistent to query reliably.
- Vendor Lock-In: A dependency state where business processes, technical integrations, and identity controls become difficult to move away from without disruption. It is not only a commercial constraint. It also creates governance friction when credentials, APIs, and monitoring workflows are tied too tightly to one provider.
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Published by the NHIMG editorial team on August 1, 2026.
Updated on October 13, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org