LibreTranslate through 1.9.7, fixed in commit 397fd22, contains an IP spoofing vulnerability in the get_remote_address() function that allows unauthenticated attackers to spoof client IP addresses by injecting arbitrary values into the X-Forwarded-For header without trusted proxy validation. Attackers can bypass per-IP rate limiting and flood bans by supplying forged addresses in the X-Forwarded-For header to enable unlimited API abuse.