Merge-State Backdoors and Plausibility Camouflage
The report corpus repeatedly highlights model merging and adapter composition as a supply-chain blind spot. A dangerous behavior may be distributed across components that look useful and benign when inspected separately.
Plausibility camouflage
A component can perform well on an ordinary task, preserve apparent utility, and pass routine checks. That usefulness is the camouflage. The unsafe behavior is not necessarily in the component alone; it may appear only when another component shifts the representation, refusal boundary, or routing condition.
Why merge state matters
A merge is not just a file operation. It creates a new model state with its own behavior. The merge coefficients, load order, base family, quantization, and prompt policy must be recorded as part of the evaluated artifact.
Safe framing
This page does not provide backdoor construction guidance. It explains why defenders cannot rely on component reputation alone.