the first cross-framework measurement (open-source mcpvenom, a 9,720-cell matrix across 12 frameworks, 18 models, 45 attack scenarios, exfiltration confirmed by canary receipt) finds a 22.9% overall attack success rate; of the vulnerable cells, 12.1% verifiably exfiltrate a secret. Resistance is model-level, not framework-level — nine core frameworks cluster at 23–26%, a code audit finds no intentional defense in any of the twelve, and all five coordinated disclosures were rejected by vendors. A regex description scanner rejects 20 of 45 scenarios at a 7.2% false-positive rate: metadata scanning alone is only a partial control.