Security teams should classify cookies by purpose, minimise non-essential tracking, and limit access to consent and session data to the systems that truly need it. Necessary cookies support login and security functions, but analytics and advertising cookies create governance, privacy, and third-party exposure risks that should be reviewed through data minimisation and vendor oversight.
Why This Matters for Security Teams
Cookie governance is not just a browser privacy issue. Session cookies, consent tokens, analytics identifiers, and advertising tags all create distinct access and tracking risks, and each one can leak sensitive context if it is over-collected or broadly shared. Security teams need a control model that separates what is required for authentication from what is merely convenient for measurement or marketing, then limits who and what can read that data.
The operational challenge is that cookie data often sits at the intersection of security, privacy, legal, and product teams. That makes ownership ambiguous, and ambiguity usually means over-retention, over-sharing, or hidden third-party exposure. The Ultimate Guide to NHIs notes that 92% of organisations expose NHIs to third parties, which is a useful warning sign for any environment where third-party scripts, tags, or identity-linked trackers can observe session metadata. Current guidance from the NIST Cybersecurity Framework 2.0 and the EU General Data Protection Regulation (GDPR) both point toward minimisation, accountability, and explicit purpose limitation, but they leave implementation details to the organisation.
In practice, many security teams discover cookie sprawl only after a browser privacy review, vendor assessment, or incident response exercise exposes how much tracking data was already flowing to systems no one had formally approved.
How It Works in Practice
A practical governance model starts by classifying cookies and adjacent browser data by purpose, not by where they are stored. Necessary cookies support authentication, CSRF protection, load balancing, and session continuity. Preference cookies support user experience. Analytics and advertising cookies support measurement and targeting, and they should be treated as higher risk because they can reveal behaviour, link users across domains, or introduce third-party access paths.
Security teams should inventory which systems can set, read, or forward each cookie category, then narrow that access to the minimum set of applications, domains, and vendors. This includes reviewing reverse proxies, tag managers, customer data platforms, analytics scripts, and support widgets. The OWASP Non-Human Identity Top 10 is relevant here because many cookie and tracking flows are ultimately machine-to-machine trust relationships, not human-to-browser decisions. The Top 10 NHI Issues also highlights how broad access and poor visibility create hidden exposure.
- Separate essential session state from optional tracking data.
- Apply purpose-based retention windows and delete data once the purpose ends.
- Restrict access to consent records and tracking logs to the systems that need them.
- Review third-party scripts and pixel vendors before allowing them to observe identifiers.
- Use policy and configuration controls to block non-essential cookies until consent is recorded.
Where possible, shift analytics toward aggregated or privacy-preserving telemetry rather than user-level identifiers, and ensure consent decisions are auditable without exposing more personal data than necessary. These controls tend to break down in heavily script-driven marketing stacks because one approved tag manager can silently reintroduce many downstream data-sharing paths.
Common Variations and Edge Cases
Tighter cookie controls often increase operational overhead, requiring organisations to balance privacy assurance against debugging friction, marketing measurement gaps, and user-experience impact. That tradeoff is real, especially when teams depend on cross-domain authentication, fraud detection, or embedded third-party services.
One common exception is fraud and security telemetry. Some identifiers that look like tracking data may actually be required to detect bot activity, prevent account takeover, or correlate risky sessions. Those use cases should be documented separately so they are not bundled into general marketing consent. Another edge case is regional law. GDPR-style purpose limitation is stricter than many legacy cookie programs were designed for, so current guidance suggests validating whether a cookie is truly necessary before treating it as exempt. Best practice is evolving for consent architecture, but there is no universal standard for how every organisation should balance banner design, script loading, and downstream vendor controls.
The most difficult environments are single-page applications, mobile-web hybrids, and ad-tech-heavy properties where tracking occurs through multiple scripts, service workers, and third-party redirects. In those cases, cookie governance should be paired with vendor review, script inventory, and periodic reassessment of whether each identifier still serves a defensible business purpose. When that discipline is missing, the result is usually not a clean privacy breach but a slow accumulation of invisible access paths.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 address the attack surface, NIST CSF 2.0, NIST SP 800-63 and NIST AI RMF set the technical controls, and EU AI Act define the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Cookies and tags often function as machine-to-machine access paths needing strict governance. |
| NIST CSF 2.0 | PR.DS-1 | Cookie data is sensitive data that should be protected in transit and at rest. |
| NIST SP 800-63 | Session cookies are part of identity assurance and require secure session handling. | |
| NIST AI RMF | Cookie governance needs documented accountability, purpose limitation, and risk oversight. | |
| EU AI Act | Not directly applicable, but useful where tracking data feeds AI-driven profiling. |
If tracking data informs AI profiling, document safeguards and limit unnecessary personal data use.
Related resources from NHI Mgmt Group
- How should security teams govern non-human identities that have persistent access?
- How should security teams govern API keys used for generative AI access?
- How should security teams govern AI-generated summaries that contain sensitive data?
- How should security teams implement policy-based access controls for ERP systems that contain sensitive personal and financial data?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 27, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
