diff --git a/openviking/server/mcp_endpoint.py b/openviking/server/mcp_endpoint.py
index 13f22ee695..5b981a9390 100644
--- a/openviking/server/mcp_endpoint.py
+++ b/openviking/server/mcp_endpoint.py
@@ -73,7 +73,7 @@
     looks_like_local_path,
 )
 from openviking.server.resource_ingest import ingest_temp_upload
-from openviking.server.routers.search import context_only_fields_error
+from openviking.server.routers.search import FiniteSearchThreshold, context_only_fields_error
 from openviking.server.skill_ingest import install_skills
 from openviking.server.temp_upload_store import TempUploadStore
 from openviking.server.upload_token_store import upload_token_store
@@ -445,7 +445,7 @@ async def find(
     query: str,
     target_uri: str = "",
     limit: int = 10,
-    min_score: float = 0.35,
+    min_score: FiniteSearchThreshold = 0.35,
     level: Optional[List[int]] = None,
     context_type: Optional[Union[str, List[str]]] = None,
     read_content: bool = False,
@@ -507,7 +507,7 @@ async def search(
     target_uri: str = "",
     session_id: Optional[str] = None,
     limit: int = 10,
-    min_score: Optional[float] = None,
+    min_score: Optional[FiniteSearchThreshold] = None,
     level: Optional[List[int]] = None,
     context_type: Optional[Union[str, List[str]]] = None,
     mode: Literal["list", "context"] = "list",
diff --git a/openviking/server/routers/search.py b/openviking/server/routers/search.py
index 26e4fe9d6d..d860651eed 100644
--- a/openviking/server/routers/search.py
+++ b/openviking/server/routers/search.py
@@ -4,7 +4,7 @@
 
 import asyncio
 import math
-from typing import Any, Dict, List, Literal, Optional, Sequence, Union
+from typing import Annotated, Any, Dict, List, Literal, Optional, Sequence, Union
 
 from fastapi import APIRouter, Depends, Request
 from fastapi import Response as FastAPIResponse
@@ -65,6 +65,7 @@ def _sanitize_floats(obj: Any) -> Any:
 
 router = APIRouter(prefix="/api/v1/search", tags=["search"])
 TimeField = Literal["updated_at", "created_at"]
+FiniteSearchThreshold = Annotated[float, Field(allow_inf_nan=False)]
 
 
 def _resolve_search_limit(limit: int, node_limit: Optional[int]) -> int:
@@ -132,7 +133,7 @@ class FindRequest(BaseModel):
     context_type: Optional[Union[str, List[str]]] = None
     limit: int = Field(default=DEFAULT_LIMIT, ge=1)
     node_limit: Optional[int] = Field(default=None, ge=1)
-    score_threshold: Optional[float] = None
+    score_threshold: Optional[FiniteSearchThreshold] = None
     filter: Optional[Dict[str, Any]] = None
     include_provenance: bool = False
     tags: Optional[List[str]] = None
@@ -226,7 +227,7 @@ class SearchRequest(BaseModel):
     session_id: Optional[str] = None
     limit: int = Field(default=DEFAULT_LIMIT, ge=1)
     node_limit: Optional[int] = Field(default=None, ge=1)
-    score_threshold: Optional[float] = None
+    score_threshold: Optional[FiniteSearchThreshold] = None
     filter: Optional[Dict[str, Any]] = None
     include_provenance: bool = False
     tags: Optional[List[str]] = None
@@ -317,7 +318,7 @@ class RecallRequest(BaseModel):
     query: str
     quotas: Optional[Dict[str, int]] = None
     max_chars: int = DEFAULT_MAX_CHARS
-    min_score: float = DEFAULT_MIN_SCORE
+    min_score: FiniteSearchThreshold = DEFAULT_MIN_SCORE
     peer_scope: Literal["actor", "all"] = "all"
     other_peer_penalty: Optional[Union[float, Dict[str, float]]] = None
     render: Union[bool, Literal["full", "compact"]] = True
@@ -328,7 +329,7 @@ class RecallRequest(BaseModel):
     max_tokens: Optional[int] = Field(default=None, ge=64, le=32000)
     purpose: Optional[Literal["chat", "coding"]] = None
     detail: Optional[DetailRequest] = None
-    score_threshold: Optional[float] = None
+    score_threshold: Optional[FiniteSearchThreshold] = None
     dedup_turns: Optional[int] = Field(default=None, ge=0, le=100)
     exclude_uris: List[str] = Field(default_factory=list, max_length=MAX_EXCLUDE_URIS)
     rewrite: Union[bool, Literal["auto"]] = False
diff --git a/openviking/server/routers/skills.py b/openviking/server/routers/skills.py
index 09659519fe..cd30820ff4 100644
--- a/openviking/server/routers/skills.py
+++ b/openviking/server/routers/skills.py
@@ -28,6 +28,7 @@
 from openviking.server.dependencies import get_service
 from openviking.server.identity import RequestContext
 from openviking.server.models import Response
+from openviking.server.routers.search import FiniteSearchThreshold
 from openviking.server.skill_package_update import (
     clear_skill_package_contents,
     transfer_skill_package,
@@ -89,7 +90,7 @@ class FindSkillsRequest(BaseModel):
 
     query: str
     limit: int = 10
-    score_threshold: Optional[float] = None
+    score_threshold: Optional[FiniteSearchThreshold] = None
     level: Optional[list[int]] = None
     telemetry: TelemetryRequest = False
     target_uri: Optional[str] = None
diff --git a/tests/server/test_search_threshold_bounds.py b/tests/server/test_search_threshold_bounds.py
new file mode 100644
index 0000000000..6f66db20b6
--- /dev/null
+++ b/tests/server/test_search_threshold_bounds.py
@@ -0,0 +1,54 @@
+# Copyright (c) 2026 Beijing Volcano Engine Technology Co., Ltd.
+# SPDX-License-Identifier: AGPL-3.0
+
+"""Public search thresholds must reject non-finite values before retrieval."""
+
+import math
+
+import pytest
+from pydantic import ValidationError
+
+import openviking.server.mcp_endpoint as mcp_endpoint
+from openviking.server.routers.search import FindRequest, RecallRequest, SearchRequest
+from openviking.server.routers.skills import FindSkillsRequest
+
+REQUEST_FIELDS = (
+    (FindRequest, "score_threshold"),
+    (SearchRequest, "score_threshold"),
+    (RecallRequest, "min_score"),
+    (RecallRequest, "score_threshold"),
+    (FindSkillsRequest, "score_threshold"),
+)
+
+
+@pytest.mark.parametrize("model,field", REQUEST_FIELDS)
+@pytest.mark.parametrize("value", (math.nan, math.inf, -math.inf))
+def test_request_models_reject_non_finite_thresholds(model, field, value):
+    with pytest.raises(ValidationError, match="finite number"):
+        model.model_validate({"query": "q", field: value})
+
+
+@pytest.mark.parametrize("model,field", REQUEST_FIELDS)
+@pytest.mark.parametrize("value", (-2.0, 2.0))
+def test_request_models_preserve_unbounded_finite_score_scales(model, field, value):
+    request = model.model_validate({"query": "q", field: value})
+
+    assert getattr(request, field) == value
+
+
+@pytest.mark.parametrize("value", ("1e999", "-1e999", "NaN"))
+def test_search_request_rejects_non_finite_json_thresholds(value):
+    with pytest.raises(ValidationError, match="finite number"):
+        SearchRequest.model_validate_json(f'{{"query":"q","score_threshold":{value}}}')
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("tool_name", ("find", "search"))
+@pytest.mark.parametrize("value", (math.nan, math.inf, -math.inf))
+async def test_mcp_tools_reject_non_finite_thresholds(tool_name, value):
+    with pytest.raises(Exception) as exc_info:
+        await mcp_endpoint.mcp.call_tool(tool_name, {"query": "q", "min_score": value})
+
+    message = str(exc_info.value)
+    assert "min_score" in message
+    assert "finite number" in message