diff --git a/x-pack/platform/plugins/shared/alerting/server/integration_tests/__snapshots__/serverless_upgrade_and_rollback_checks.test.ts.snap b/x-pack/platform/plugins/shared/alerting/server/integration_tests/__snapshots__/serverless_upgrade_and_rollback_checks.test.ts.snap
index be93556deb7d6..719dcd917211c 100644
--- a/x-pack/platform/plugins/shared/alerting/server/integration_tests/__snapshots__/serverless_upgrade_and_rollback_checks.test.ts.snap
+++ b/x-pack/platform/plugins/shared/alerting/server/integration_tests/__snapshots__/serverless_upgrade_and_rollback_checks.test.ts.snap
@@ -6097,6 +6097,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
@@ -6768,6 +6786,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
@@ -7502,6 +7538,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
@@ -8154,6 +8208,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
@@ -8862,6 +8934,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
@@ -9571,6 +9661,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
@@ -10280,6 +10388,24 @@ Object {
             Object {
               "additionalProperties": false,
               "properties": Object {
+                "customizedFields": Object {
+                  "items": Object {
+                    "additionalProperties": false,
+                    "properties": Object {
+                      "fieldName": Object {
+                        "type": "string",
+                      },
+                    },
+                    "required": Array [
+                      "fieldName",
+                    ],
+                    "type": "object",
+                  },
+                  "type": "array",
+                },
+                "hasBaseVersion": Object {
+                  "type": "boolean",
+                },
                 "isCustomized": Object {
                   "type": "boolean",
                 },
diff --git a/x-pack/solutions/security/plugins/security_solution/server/lib/detection_engine/rule_schema/model/rule_schemas.ts b/x-pack/solutions/security/plugins/security_solution/server/lib/detection_engine/rule_schema/model/rule_schemas.ts
index c1192e9a75fd1..ae9faa8bb006a 100644
--- a/x-pack/solutions/security/plugins/security_solution/server/lib/detection_engine/rule_schema/model/rule_schemas.ts
+++ b/x-pack/solutions/security/plugins/security_solution/server/lib/detection_engine/rule_schema/model/rule_schemas.ts
@@ -104,6 +104,14 @@ export const RuleSourceCamelCased = z.discriminatedUnion('type', [
   z.object({
     type: z.literal('external'),
     isCustomized: IsExternalRuleCustomized,
+    customizedFields: z
+      .array(
+        z.object({
+          fieldName: z.string(),
+        })
+      )
+      .optional(),
+    hasBaseVersion: z.boolean().optional(),
   }),
   z.object({
     type: z.literal('internal'),