REDDIT · REDDIT// 32d agoSECURITY INCIDENT

GPT-5.4 regresses on prompt injection

OpenAI's GPT-5.4 safety materials show improved resistance to prompt injection through email connectors but a slight regression on attacks targeting function cells. Third-party testing from AgentSeal also ranks GPT-5.4 near the top overall, yet gives it only 50% injection resistance, reinforcing that prompt injection remains a live weakness in agent-style workflows.

// ANALYSIS

The story here is not that GPT-5.4 is uniquely unsafe — it's that frontier models still crack where tools, connectors, and external content can smuggle instructions back into the loop. Better reasoning helps, but it does not solve agent security by itself.

–OpenAI's own system card explicitly says GPT-5.4 improved on email-connector prompt injection and regressed slightly on function-cell attacks
–AgentSeal ranks GPT-5.4 second overall with an 87.5 trust score, but its injection-resistance slice is only 50%, far below its perfect extraction and boundary scores
–Agent builders should treat tool output, MCP responses, spreadsheets, and retrieved content as untrusted input rather than model-readable truth
–The practical takeaway for developers is still the same: sanitize tool outputs, scope permissions tightly, and require confirmation before high-impact actions

// TAGS

gpt-5-4llmsafetyagentapi

DISCOVERED

32d ago

2026-03-10

PUBLISHED

36d ago

2026-03-07

RELEVANCE

9/ 10

AUTHOR

MeetReady6307