CVE-2025-68949: n8n: Webhook Node IP `Whitelist` Bypass via Partial String Matching

The Webhook node’s IP whitelist validation performed partial string matching instead of exact IP comparison. As a result, an incoming request could be accepted if the source IP address merely contained the configured whitelist entry as a substring.

This issue affected instances where workflow editors relied on IP-based access controls to restrict webhook access. Both IPv4 and IPv6 addresses were impacted. An attacker with a non-whitelisted IP could bypass restrictions if their IP shared a partial prefix with a trusted address, undermining the intended security boundary.