diff --git a/backend/package/yuxi/utils/net_security.py b/backend/package/yuxi/utils/net_security.py
index 4167fbc3..084f07f7 100644
--- a/backend/package/yuxi/utils/net_security.py
+++ b/backend/package/yuxi/utils/net_security.py
@@ -76,6 +76,8 @@ class SSRFPolicy(BaseModel):
 
     _blocked_networks: list[ipaddress.IPv4Network | ipaddress.IPv6Network] = PrivateAttr(default_factory=list)
     _blocked_domains_normalized: set[str] = PrivateAttr(default_factory=set)
+    _blocked_hostnames_normalized: set[str] = PrivateAttr(default_factory=set)
+    _blocked_hostname_suffixes_normalized: list[str] = PrivateAttr(default_factory=list)
 
     model_config = {"arbitrary_types_allowed": True}
 
@@ -86,6 +88,12 @@ class SSRFPolicy(BaseModel):
         self._blocked_domains_normalized = {
             _normalize_hostname(d) for d in self.blocked_domains
         }
+        self._blocked_hostnames_normalized = {
+            _normalize_hostname(h) for h in self.blocked_hostnames
+        }
+        self._blocked_hostname_suffixes_normalized = [
+            _normalize_hostname(s) for s in self.blocked_hostname_suffixes
+        ]
 
 
 class SSRFBlockedError(Exception):
@@ -109,9 +117,9 @@ def _is_blocked_hostname(hostname: str, policy: SSRFPolicy) -> bool:
     normalized = _normalize_hostname(hostname)
     if not normalized:
         return True  # fail-closed
-    if normalized in policy.blocked_hostnames:
+    if normalized in policy._blocked_hostnames_normalized:
         return True
-    return any(normalized.endswith(suffix) for suffix in policy.blocked_hostname_suffixes)
+    return any(normalized.endswith(suffix) for suffix in policy._blocked_hostname_suffixes_normalized)
 
 
 def _matches_domain_pattern(hostname: str, pattern: str) -> bool: