PraisonAI is a multi-agent teams system. Prior to version 4.6.40 of PraisonAI, corresponding to version 1.6.40 of praisonaiagents, "spider_tools" URL validation can be bypassed using alternate loopback host encodings. The tool contains a URL validation function intended to block local or unsafe targets before fetching attacker-controlled URLs. However, the validation only blocks a small set of exact host strings such as "localhost" and "127.0.0.1". It does not normalize hostnames, resolve DNS, parse numeric IPv4 variants, or validate the final resolved IP address before making the request. As a result, certain URLs may bypass the protection and still reach loopback services. After the weak validation passes, "scrape_page()" calls "requests.Session.get()" on the attacker-controlled URL. This allows an attacker who can influence URLs passed to "scrape_page", "crawl", or "extract_text" to induce SSRF requests against loopback-only services. This is a server-side request forgery protection bypass. PraisonAI version 4.6.40 and praisonaiagents version 1.6.40 contain a patch.