Patched code sample

import re
import socket
from urllib.parse import urlparse, urlunparse

from playwright.sync_api import sync_playwright

PRIVATE_IP_RE = re.compile(
    r"^(10\.|172\.(1[6-9]|2[0-9]|3[0-1])\.|192\.168\.)"
)

class SafePlaywrightURLLoader:
    def __init__(self):
        self.playwright = sync_playwright().start()
        self.browser = self.playwright.chromium.launch()

    def _is_private(self, hostname: str) -> bool:
        try:
            ip = socket.gethostbyname(hostname)
            return bool(PRIVATE_IP_RE.match(ip))
        except Exception:
            return False

    # FIX: resolve hostname once and use the same IP for the request
    def load(self, url: str) -> str:
        parsed = urlparse(url)
        hostname = parsed.hostname or ""
        if self._is_private(hostname):
            raise ValueError("Private host not allowed")

        ip = socket.gethostbyname(hostname)
        safe_netloc = f"{ip}:{parsed.port}" if parsed.port else ip
        safe_url = urlunparse(parsed._replace(netloc=safe_netloc))

        page = self.browser.new_page()
        page.route("**/*", lambda route: route.continue_(
            url=safe_url,
            headers={"host": hostname}
        ))
        page.goto(safe_url)
        content = page.content()
        page.close()
        return content