security: harden default error handler — safe-by-default#51
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May 13, 2026 20:08
BREAKING: DEFAULT_ERROR_HANDLER now only exposes error details in NODE_ENV=development (opt-in). All other modes — production, staging, testing, and unset NODE_ENV — return sanitized "Internal Server Error". Previously, any mode except production leaked err.message to clients, which could expose DB queries, file paths, or internal state. Changes: - lib/router/sequential.js: flip condition from === 'production' to === 'development', add Content-Type header - tests/nested-routers.test.js: expect sanitized response in test mode - tests/router-coverage.test.js: expect sanitized response in test mode - tests/v4.4.test.js: add NODE_ENV-unset test - tooling/pentest.js: comprehensive 48-vector security test suite Pen test results: 48/48 passed, 0 findings (post-fix) Test suite: 64/64 passed, 97.7% coverage
- Remove unused requires (http, url)
- Remove unused variables (checkPrototypePollution, timeout, nested→const)
- Fix trailing commas (standard style)
- Fix quotes (single quotes for strings)
- Fix dot notation (res.getHeader('server') not ['server'])
- Fix _body getter (captures mock response body correctly)
- Convert template literals to string concatenation for standard
molty3000
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May 14, 2026
BREAKING: DEFAULT_ERROR_HANDLER now safe-by-default. Only NODE_ENV=development exposes error details. See PR #51 for the security hardening fix.
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BREAKING: DEFAULT_ERROR_HANDLER now only exposes error details in NODE_ENV=development (opt-in). All other modes — production, staging, testing, and unset NODE_ENV — return sanitized "Internal Server Error".
Previously, any mode except production leaked err.message to clients, which could expose DB queries, file paths, or internal state.
Changes:
Pen test results: 48/48 passed, 0 findings (post-fix)
Test suite: 64/64 passed, 97.7% coverage