guide · Evidence checked 2026-09-02
A search result title can be a data leak
A practical, evidence-led decision guide. Product capabilities and limits are separated from anything that would require hands-on testing.
Permission-aware search can truthfully respect source permissions and still leak information when the source ACLs are stale, group mappings are wrong or snippets reveal a denied document. Security testing must start before relevance testing.
Build an adversarial corpus
Create documents covering direct allow, direct deny, nested groups, inherited access, guest access, public links and recently revoked users. Put a unique sentinel in each title and body. Use at least four identities with deliberately overlapping membership.
Test exact title, synonym and question queries. Record whether title, snippet, answer, citation and autocomplete reveal the sentinel. Explicit deny must win. Unspecified access must fail closed where the product promises that model. Then revoke a user's access and measure disappearance from source, index, cache, suggestions and generated answers.
Run the same fixture against Glean, Coveo or Microsoft Copilot. Do not let a vendor replace it with a clean demo tenant.
The release gate is binary: zero unauthorized disclosure, documented revocation latency and an owner for every connector. Relevance scores come afterward.