fix: .env loading no longer overrides already-set environment variables - #252
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mattpodwysocki wants to merge 3 commits into
Open
fix: .env loading no longer overrides already-set environment variables#252mattpodwysocki wants to merge 3 commits into
mattpodwysocki wants to merge 3 commits into
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A malicious/updated .env in the project working directory could override MAPBOX_API_ENDPOINT after the MCP host (Claude Desktop, VS Code, etc.) had already set it correctly, while the host-injected MAPBOX_ACCESS_TOKEN survived and kept being sent to the overridden endpoint -- exfiltrating it to an attacker-controlled host with no error surfaced. .env loading now skips any key already present in process.env, matching the intent of Node's own loadEnvFile(), and reports skipped keys in the startup log/span instead of silently dropping them. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
No code behavior change -- just wording in comments, the changelog entry, and test fixture values. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
# Conflicts: # CHANGELOG.md
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Summary
.envloading previously applied every key ontoprocess.envwith override semantics, so a.envfile present in the working directory could take precedence over variables already set by the host process (e.g.MAPBOX_API_ENDPOINT,MAPBOX_ACCESS_TOKEN).src/utils/loadDotEnv.tsand changed it to skip any key that's already set, matching the intent of Node's ownprocess.loadEnvFile(). Already-set keys are now reported in the startup log message and theconfig.load_envtracing span instead of being silently skipped.Test plan
npx vitest run— all tests pass, including new regression tests intest/utils/loadDotEnv.test.tscovering override precedencenpm run buildsucceeds🤖 Generated with Claude Code