Package Instance

@langchain/community affected by SSRF Bypass in RecursiveUrlLoader via insufficient URL origin validation
The `RecursiveUrlLoader` class in `@langchain/community` is a web crawler that recursively follows links from a starting URL. Its `preventOutside` option (enabled by default) is intended to restrict crawling to the same site as the base URL.

The implementation used `String.startsWith()` to compare URLs, which does not perform semantic URL validation. An attacker who controls content on a crawled page could include links to domains that share a string prefix with the target (e.g., `https://example.com.attacker.com` passes a `startsWith` check against `https://example.com`), causing the crawler to follow links to attacker-controlled or internal infrastructure.

Additionally, the crawler performed no validation against private or reserved IP addresses. A crawled page could include links targeting cloud metadata services (`169.254.169.254`), localhost, or RFC 1918 addresses, and the crawler would fetch them without restriction.