Fix the control, not the payload
A blocklist that rejects the original string may leave the dangerous operation reachable through a variant. Identify the missing authorization decision, unsafe data boundary, or insecure primitive, and repair that cause.
Turn evidence into a regression test
Where safe, encode the expected denial or validation behavior in automated tests. Include adjacent roles, tenants, object states, and encoding variants that express the same trust property.
Retest in a representative environment
Configuration, middleware, gateways, deployed versions, and identity providers affect exploitability. Record the revision and environment so a passing result has interpretable boundaries.
Check for bypass and side effects
Verify both that the original harmful result is gone and that the legitimate workflow still works. Review nearby code paths that share the same control to avoid moving the defect.
State the conclusion precisely
Prefer: the reported cross-tenant export path did not reproduce for the tested roles on revision X. Avoid: the application is secure. Precision preserves trust and guides the next assessment decision.