diff --git a/src/components/image-editor/model3d-generation/Model3dGenerationFormModel.test.ts b/src/components/image-editor/model3d-generation/Model3dGenerationFormModel.test.ts
index f7cd7c859..c22199f3b 100644
--- a/src/components/image-editor/model3d-generation/Model3dGenerationFormModel.test.ts
+++ b/src/components/image-editor/model3d-generation/Model3dGenerationFormModel.test.ts
@@ -265,6 +265,12 @@ describe('模型版本', () => {
     expect(normalizeModel3dModelVersion(null)).toBe(
       DEFAULT_MODEL3D_MODEL_VERSION,
     );
+    // 原型链上的键（`in` 会命中）不是契约版本，同样按默认版本处理。
+    for (const inheritedKey of ['toString', 'constructor', '__proto__']) {
+      expect(normalizeModel3dModelVersion(inheritedKey)).toBe(
+        DEFAULT_MODEL3D_MODEL_VERSION,
+      );
+    }
   });
 
   it('可选项只给当前端点有底价的版本，顺序按契约声明', () => {
diff --git a/src/components/image-editor/model3d-generation/Model3dGenerationValidation.ts b/src/components/image-editor/model3d-generation/Model3dGenerationValidation.ts
index 303ba027d..d7f5b2c9f 100644
--- a/src/components/image-editor/model3d-generation/Model3dGenerationValidation.ts
+++ b/src/components/image-editor/model3d-generation/Model3dGenerationValidation.ts
@@ -53,7 +53,9 @@ export const MODEL3D_MODEL_VERSIONS = Object.keys(
 export function isModel3dModelVersion(
   value: string,
 ): value is Model3dModelVersion {
-  return value in MODEL3D_MODEL_TABLE;
+  // 用自有属性判断而不是 `in`：`in` 会把 `toString` / `__proto__` 这类原型链上的键也算命中，
+  // 之后按版本查表会拿到 undefined。
+  return Object.hasOwn(MODEL3D_MODEL_TABLE, value);
 }
 
 export function resolveModel3dModelLabel(model: Model3dModelVersion): string {