Claude Sonnet Blocks 1 Legitimate Cybersecurity Skill as Broad Guardrails Misfire
Updated
Updated · O'Reilly Media · Aug 19
Claude Sonnet Blocks 1 Legitimate Cybersecurity Skill as Broad Guardrails Misfire
2 articles · Updated · O'Reilly Media · Aug 19
Summary
A Claude Sonnet skill that had run daily for months suddenly failed after safeguards flagged it as cybersecurity-related, even though it only compiled article digests from about a dozen public tech news sites.
The trigger was a source description containing “vulnerabilities, exploits, threat reporting” — language Claude itself had generated for Hacker News — which Sonnet treated as risky enough to block the skill.
Editing the description fixed the skill only in a new Sonnet session; the original conversation stayed permanently blocked because Sonnet scores security risk across the entire chat context, not just the single tool call.
Haiku and GPT 5.6 handled a similar workflow without issue, underscoring the complaint that Sonnet’s newer safeguards are producing false positives and unpredictable breakage for legitimate work.
The report argues that unclear, shifting guardrail boundaries make AI tools less reliable in production, especially when safety rules can disable benign tasks with no advance warning.