{"schema":"immunity/antibody-envelope/v1","keccakId":"0xd335d3e9bd029f960ef8ae4c550feaabe51352a581118713428c92993cbc684e","immId":"","abType":"SEMANTIC","flavor":2,"publisher":"0x4789ddae13d7cbf11aa97d39b201d973d01cbc28","createdAt":"2026-04-29T17:32:17.835Z","reasonSummary":"HTML-style closing tag for a system role marker, used to break out of role boundaries in agents that use angle-bracket conversation templates. The attack relies on the parser eagerly consuming the tag from inside untrusted content rather than treating it as data. MALICIOUS at high confidence: the construct has no legitimate use in user-supplied or retrieved content, and a single appearance is sufficient for the antibody to fire.","matcher":{"kind":"semantic","flavor":"PROMPT_INJECTION","markerHint":"</system>"}}