PENGO Workbench
Workbench / Patterns / Boundary Leakage

PAT-0140

Boundary Leakage

A structural condition where effects, permissions, state, data, or authority cross a declared boundary without an authorized exception.

Primary Lenses

LEN-0220

Isolation Boundary Lens

Evaluates whether structural constraints, effects, and regions remain contained within declared boundaries.

Lens Application

The Isolation Boundary Lens is a strong inspection mechanism for Boundary Leakage because it focuses attention on whether declared isolation regions actually constrain movement of effects, permissions, state, data, and authority. It helps inspect whether any cross-boundary behavior is explicitly authorized.

Inspect For

  • Effects escaping declared regions
  • Shared state or data crossing boundaries
  • Permission or authority bleed-through
  • Missing or implicit boundary exceptions

Avoid

Treat cross-boundary behavior as an inspection signal, not proof that Boundary Leakage is present.

LEN-0250

Propagation Lens

Traces how structural declarations, effects, or state changes propagate across boundaries or stages.

Lens Application

The Propagation Lens is a strong inspection mechanism for Boundary Leakage because it follows effects, permissions, state, data, and authority as they move across boundaries, stages, or scopes. It helps surface where propagation exceeds the intended scope, skips an exception path, or carries authority into places not authorized by the boundary.

Inspect For

  • Effects crossing boundary edges without an explicit exception
  • Permissions or authority persisting beyond intended scope
  • State or data copied into downstream stages unexpectedly
  • Boundary checks that occur after propagation has already happened

Avoid

Treat propagation evidence as a signal for closer inspection, not confirmation that Boundary Leakage has occurred.

Secondary Lenses

LEN-0120

Boundary Compliance Lens

Evaluates observed structure against declared boundary posture, including allow, block, and exception rules.

Lens Application

The Boundary Compliance Lens applies indirectly to Boundary Leakage by checking whether effects, permissions, state, data, or authority cross declared boundaries in ways that match the stated boundary posture. It helps surface crossings that lack allow rules, appear to bypass block rules, or require exception review.

Inspect For

  • Cross-boundary flows without matching allow rules
  • Permissions or authority extending beyond declared scope
  • State or data movement relying on unclear exceptions
  • Block rules bypassed by informal paths

Avoid

Treat boundary posture mismatches as review signals, not proof that Boundary Leakage has occurred.

Primary Issue Matches

Supporting Issue Matches

ISS-0046

Action Changed Something Else Too

An AI or agent action makes the requested change but also changes another object, field, file, state, rule, or workflow element that was not supposed to change.

ISS-0109

AI Memory Has No Governance

Saved or persistent AI memory affects output without clear rules for ownership, scope, review, update, expiry, or removal.

ISS-0114

AI Memory Updated Without Asking

AI memory, saved context, preference, or durable state is updated without the user clearly asking for or approving that update.

ISS-0045

AI Touches Unrelated Scope

The AI affects, edits, analyzes, changes, or reasons over material outside the scope of the requested task.

ISS-0039

Hidden Rule Overrides Visible Instruction

A hidden, upstream, system, policy, tool, or product rule changes or overrides the visible instruction the user expects the AI to follow.

ISS-0101

Local Exception Grows Into Policy

A local exception, special case, or one-off allowance begins to function like a general policy.

ISS-0096

Local Rule Spreads to Broader Cases

A rule intended for one local case, file, context, user, workflow, or exception begins affecting broader cases.

ISS-0049

Policy Exception Spreads Too Far

A narrow policy exception, allowance, or special case spreads beyond its intended scope and begins governing broader cases.

ISS-0076

Prompt Does Not Say What to Exclude

The prompt declares what to include but does not declare what should be excluded, allowing unwanted scope, sources, content, or actions into the result.

ISS-0112

Routing Overrides Task Intent

Routing, mode selection, agent behavior, or workflow classification sends the task down a path that overrides what the user was trying to accomplish.