Claude Opus 5 achieves zero percent success in browser prompt-injection tests
July 26, 2026
Anthropic reports that Claude Opus 5 demonstrates near-total immunity to browser-based prompt-injection attacks. In specific testing scenarios, the model maintained a zero percent success rate against these exploits.
HOW THIS AFFECTS YOU
●
builderYou can more safely integrate this model into browser-based workflows and agentic tasks.
●
policyThis represents a significant step forward in mitigating LLM-based security vulnerabilities.