diff --git a/x-pack/plugins/cases/common/api/runtime_types.ts b/x-pack/plugins/cases/common/api/runtime_types.ts
index c807d4b31b75150..0a31479b29da899 100644
--- a/x-pack/plugins/cases/common/api/runtime_types.ts
+++ b/x-pack/plugins/cases/common/api/runtime_types.ts
@@ -9,42 +9,18 @@ import { either, fold } from 'fp-ts/lib/Either';
 import { identity } from 'fp-ts/lib/function';
 import { pipe } from 'fp-ts/lib/pipeable';
 import * as rt from 'io-ts';
-import { isObject } from 'lodash/fp';
+import { formatErrors } from '@kbn/securitysolution-io-ts-utils';
 
 type ErrorFactory = (message: string) => Error;
-
-/**
- * @deprecated Use packages/kbn-securitysolution-io-ts-utils/src/format_errors/index.ts
- * Bug fix for the TODO is in the format_errors package
- */
-export const formatErrors = (errors: rt.Errors): string[] => {
-  const err = errors.map((error) => {
-    if (error.message != null) {
-      return error.message;
-    } else {
-      const keyContext = error.context
-        .filter(
-          (entry) => entry.key != null && !Number.isInteger(+entry.key) && entry.key.trim() !== ''
-        )
-        .map((entry) => entry.key)
-        .join(',');
-
-      const nameContext = error.context.find((entry) => {
-        // TODO: Put in fix for optional chaining https://github.com/cypress-io/cypress/issues/9298
-        if (entry.type && entry.type.name) {
-          return entry.type.name.length > 0;
-        }
-        return false;
-      });
-      const suppliedValue =
-        keyContext !== '' ? keyContext : nameContext != null ? nameContext.type.name : '';
-      const value = isObject(error.value) ? JSON.stringify(error.value) : error.value;
-      return `Invalid value "${value}" supplied to "${suppliedValue}"`;
-    }
-  });
-
-  return [...new Set(err)];
-};
+export type GenericIntersectionC =
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  | rt.IntersectionC<[any, any]>
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  | rt.IntersectionC<[any, any, any]>
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  | rt.IntersectionC<[any, any, any, any]>
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  | rt.IntersectionC<[any, any, any, any, any]>;
 
 export const createPlainError = (message: string) => new Error(message);
 
@@ -57,6 +33,40 @@ export const decodeOrThrow =
   (inputValue: I) =>
     pipe(runtimeType.decode(inputValue), fold(throwErrors(createError), identity));
 
+const getProps = (
+  codec:
+    | rt.HasProps
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    | rt.RecordC<rt.StringC, any>
+    | GenericIntersectionC
+): rt.Props | null => {
+  if (codec == null) {
+    return null;
+  }
+  switch (codec._tag) {
+    case 'DictionaryType':
+      if (codec.codomain.props != null) {
+        return codec.codomain.props;
+      }
+      const dTypes: rt.HasProps[] = codec.codomain.types;
+      return dTypes.reduce<rt.Props>((props, type) => Object.assign(props, getProps(type)), {});
+    case 'RefinementType':
+    case 'ReadonlyType':
+      return getProps(codec.type);
+    case 'InterfaceType':
+    case 'StrictType':
+    case 'PartialType':
+      return codec.props;
+    case 'IntersectionType':
+      const iTypes = codec.types as rt.HasProps[];
+      return iTypes.reduce<rt.Props>((props, type) => {
+        return Object.assign(props, getProps(type) as rt.Props);
+      }, {} as rt.Props) as rt.Props;
+    default:
+      return null;
+  }
+};
+
 const getExcessProps = (props: rt.Props, r: Record<string, unknown>): string[] => {
   const ex: string[] = [];
   for (const k of Object.keys(r)) {
@@ -67,15 +77,21 @@ const getExcessProps = (props: rt.Props, r: Record<string, unknown>): string[] =
   return ex;
 };
 
-export function excess<C extends rt.InterfaceType<rt.Props> | rt.PartialType<rt.Props>>(
-  codec: C
-): C {
+export function excess<
+  C extends rt.InterfaceType<rt.Props> | GenericIntersectionC | rt.PartialType<rt.Props>
+>(codec: C): C {
+  const codecProps = getProps(codec);
+
   const r = new rt.InterfaceType(
     codec.name,
     codec.is,
     (i, c) =>
       either.chain(rt.UnknownRecord.validate(i, c), (s: Record<string, unknown>) => {
-        const ex = getExcessProps(codec.props, s);
+        if (codecProps == null) {
+          return rt.failure(i, c, 'unknown codec');
+        }
+
+        const ex = getExcessProps(codecProps, s);
         return ex.length > 0
           ? rt.failure(
               i,
@@ -87,7 +103,7 @@ export function excess<C extends rt.InterfaceType<rt.Props> | rt.PartialType<rt.
           : codec.validate(i, c);
       }),
     codec.encode,
-    codec.props
+    codecProps
   );
   return r as C;
 }
diff --git a/x-pack/plugins/cases/server/client/cases/create.ts b/x-pack/plugins/cases/server/client/cases/create.ts
index e11bfdba06c1d1c..917acb1337b6cbb 100644
--- a/x-pack/plugins/cases/server/client/cases/create.ts
+++ b/x-pack/plugins/cases/server/client/cases/create.ts
@@ -19,6 +19,7 @@ import {
   CasePostRequest,
   ActionTypes,
   CasePostRequestRt,
+  excess,
 } from '../../../common/api';
 import { MAX_TITLE_LENGTH } from '../../../common/constants';
 import { isInvalidTag } from '../../../common/utils/validators';
@@ -47,7 +48,7 @@ export const create = async (
   } = clientArgs;
 
   const query = pipe(
-    CasePostRequestRt.decode({
+    excess(CasePostRequestRt).decode({
       ...data,
     }),
     fold(throwErrors(Boom.badRequest), identity)