{"schema":"postcutoff/event@1","as_of":"2026-11-09T21:13:00+01:00","url":"https://postcutoff.com/e/2026-11-05-claude-code-email-in-user-agent-bug/","md":"https://postcutoff.com/e/2026-11-05-claude-code-email-in-user-agent-bug/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2026-11-05-claude-code-email-in-user-agent-bug","date":"2026-11-05","date_precision":"day","short_title":"Claude Code users find their email address sent to websites in User-Agent headers","deck":"Anthropic says a default privacy mod blocks it","takeaway":null,"category":"agents","category_label":"Agents","importance":2,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"GitHub: anthropics/claude-code #107757","url":"https://github.com/anthropics/claude-code/issues/107757","type":"code","group":"primary","domain":"github.com"},{"n":2,"title":"Hacker News discussion","url":"https://news.ycombinator.com/item?id=50385272","type":"discussion","group":"reactions","domain":"news.ycombinator.com"}],"official":1,"filed":"2026-11-06","updated":"2026-11-06","orgs":["Anthropic"],"title":"Claude Code users find their email address sent to websites in User-Agent headers; Anthropic says a default privacy mod blocks it","summary":"A GitHub issue opened Nov 5, 2026 (1,228 HN points) reported that Claude Code agents put users' email addresses into User-Agent headers when fetching websites, mostly from sub-agents running curl; an Anthropic contributor said a built-in 'cc-plugin-privacy' mod, on by default since v2.1.317, blocks it.","key_facts":["Issue #107757, labelled bug and area:security","One user found 53 affected calls across 8 sessions (Aug–Nov 2026)","Reporter attributes dozens of daily scam emails to it"],"key_numbers":[],"tags":["claude-code","privacy","bug"],"science":null,"body_md":"## What happened\n\nSee summary.","disputed":[],"related":[{"id":"2026-09-23-claude-code-agents-md-telemetry-bug","url":"https://postcutoff.com/e/2026-09-23-claude-code-agents-md-telemetry-bug/","date":"2026-09-23","date_precision":"day","short_title":"Claude Code silently ignored AGENTS.md when telemetry was off","deck":"Fixed in v2.1.281","takeaway":"A small bug, but a clear example of how remote feature flags can make an agent's behavior depend on unrelated privacy settings.","category":"product","category_label":"Products","importance":2,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":2,"official":0,"filed":"2026-09-30","updated":"2026-09-30","orgs":["Anthropic"]}],"people":[],"posts":[],"videos":[],"models":[],"changes":[{"date":"2026-11-06","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-11-06","run":null,"sources_read":null,"updated":"2026-11-06","human_review":null,"version":{"date":"2026-11-06"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":189,"in_training_data":false},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":128,"in_training_data":false},{"model_id":"gemini-4-argon","name":"Gemini 4 Argon","cutoff":"2026-03","days_after":219,"in_training_data":false},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":158,"in_training_data":false}],"short_url":null}