fix(proxy): mask IPv6 addresses that end or start with :: across eight groups

The masking pattern allowed seven colons, so valid forms like 1:2:3:4:5:6:7::
and ::1:2:3:4:5:6:7 stayed in stored error text with
disable_requester_ip_address_logging on. Also lists the request metadata walker
in the recursion check, since it only walks the tree the spend log sanitizer
already returned.

litellm/proxy/spend_tracking/spend_tracking_utils.py

@@ -1625,7 +1625,7 @@ _REQUEST_METADATA_KEYS: Final = ("metadata", "litellm_metadata")
 _OBJECT_MAPPING: Final = TypeAdapter(Mapping[object, object])
 _OBJECT_LIST: Final = TypeAdapter(list[object])
 _IPV4_ADDRESS: Final = re.compile(r"\b(?:\d{1,3}\.){3}\d{1,3}\b")
-_IPV6_ADDRESS_CANDIDATE: Final = re.compile(r"(?<![\w:])(?:[0-9A-Fa-f]{0,4}:){2,7}[0-9A-Fa-f]{0,4}(?![\w:])")
+_IPV6_ADDRESS_CANDIDATE: Final = re.compile(r"(?<![\w:])(?:[0-9A-Fa-f]{0,4}:){2,8}[0-9A-Fa-f]{0,4}(?![\w:])")
 
 
 def _masked_ipv6_address(candidate: re.Match[str]) -> str:

tests/code_coverage_tests/recursive_detector.py

@@ -80,6 +80,7 @@ IGNORE_FUNCTIONS = [
     "_replace_string_leaves",  # bounded by the nesting depth of a safe_json_structure output (a finite JSON tree, no cycles possible).
     "_sort_processed_sets",  # bounded by the nesting depth of the log-record extra it walks (a finite JSON tree, no cycles possible).
     "scrub_json_strings",  # max depth set (MAX_SCRUB_DEPTH); fails closed by returning "[Filtered]" for anything nested past the cap.
+    "_without_requester_ip_address",  # walks only the fresh tree _sanitize_request_body_for_spend_logs_payload returns (mapping cycles already cut), so it never goes deeper than that sanitizer did.
 ]
 
 

tests/unit/proxy/spend_tracking/test_spend_tracking_utils.py

@@ -6701,3 +6701,28 @@ def test_failure_error_information_masks_ip_addresses_before_long_text_is_trunca
         assert LITELLM_TRUNCATED_PAYLOAD_FIELD in stored_text
         assert any(char.isdigit() for char in kept_head_and_tail) is not disabled
     assert sanitized["error_code"] == "500"
+
+
+@pytest.mark.parametrize(
+    "address", ["203.0.113.9", "2001:db8::9", "1:2:3:4:5:6:7:8", "1:2:3:4:5:6:7::", "::1:2:3:4:5:6:7", "fe80::1"]
+)
+def test_failure_error_information_masks_every_ip_address_form_when_ip_logging_is_disabled(
+    monkeypatch: pytest.MonkeyPatch, address: str
+) -> None:
+    from litellm.proxy.proxy_server import general_settings
+
+    monkeypatch.setitem(general_settings, "disable_requester_ip_address_logging", True)
+
+    sanitized: Final = sanitize_error_information_for_spend_logs(
+        {
+            "error_code": "403",
+            "error_message": f"IP address {address} not allowed.",
+            "traceback": f"peer [{address}]:443",
+        }
+    )
+
+    assert sanitized == {
+        "error_code": "403",
+        "error_message": "IP address REDACTED_BY_LITELM not allowed.",
+        "traceback": "peer [REDACTED_BY_LITELM]:443",
+    }