10 of 11 AI coding agents fell to the same shell trick

Summary

Adversa AI disclosed GuardFall on 30 June 2026. Their bypasses got past the command filter in 10 of 11 open-source coding and computer-use agents. One held, Continue, and it held because it parses the command before judging it, rather than matching patterns in raw text. The trick is decades old. The guard inspects the string the model produced, and bash rewrites that string before running it. A regex reads r''m and finds nothing to match, then bash strips the quotes and runs rm. $IFS expansi...