diff --git a/packages/core/http/core-http-server-internal/src/csp/csp_directives.test.ts b/packages/core/http/core-http-server-internal/src/csp/csp_directives.test.ts
index e250a6b1fea44..d430962053ceb 100644
--- a/packages/core/http/core-http-server-internal/src/csp/csp_directives.test.ts
+++ b/packages/core/http/core-http-server-internal/src/csp/csp_directives.test.ts
@@ -121,5 +121,28 @@ describe('CspDirectives', () => {
         `"script-src 'report-sample' 'self' 'unsafe-hashes'; worker-src 'report-sample' 'self' blob:; style-src 'report-sample' 'self' 'unsafe-inline'"`
       );
     });
+
+    it('merges additional CSP configs as expected', () => {
+      const config = cspConfig.schema.validate({
+        connect_src: ['*.foo.bar'], // should de-dupe these
+      });
+      const additionalConfig1 = {
+        connect_src: ['*.foo.bar'],
+        img_src: ['*.foo.bar'],
+      };
+      const additionalConfig2 = {
+        connect_src: [`cdn.host.test`],
+        font_src: [`cdn.host.test`],
+        frame_src: [`cdn.host.test`],
+        img_src: [`cdn.host.test`],
+        worker_src: [`cdn.host.test`],
+        script_src: [`cdn.host.test`],
+        style_src: [`cdn.host.test`],
+      };
+      const directives = CspDirectives.fromConfig(config, additionalConfig1, additionalConfig2);
+      expect(directives.getCspHeader()).toEqual(
+        `script-src 'report-sample' 'self' cdn.host.test; worker-src 'report-sample' 'self' blob: cdn.host.test; style-src 'report-sample' 'self' 'unsafe-inline' cdn.host.test; connect-src 'self' *.foo.bar cdn.host.test; font-src 'self' cdn.host.test; frame-src 'self' cdn.host.test; img-src 'self' *.foo.bar cdn.host.test`
+      );
+    });
   });
 });
diff --git a/packages/core/http/core-http-server-internal/src/csp/csp_directives.ts b/packages/core/http/core-http-server-internal/src/csp/csp_directives.ts
index d7495e4c09bfc..21b2f7c573e33 100644
--- a/packages/core/http/core-http-server-internal/src/csp/csp_directives.ts
+++ b/packages/core/http/core-http-server-internal/src/csp/csp_directives.ts
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-import { merge } from 'lodash';
+import deepmerge from 'deepmerge';
 import { CspConfigType } from './config';
 
 export type CspDirectiveName =
@@ -70,7 +70,10 @@ export class CspDirectives {
     firstConfig: CspConfigType,
     ...otherConfigs: Array<Partial<CspConfigType>>
   ): CspDirectives {
-    const config = otherConfigs.length ? merge(firstConfig, ...otherConfigs) : firstConfig;
+    const config = otherConfigs.reduce<CspConfigType>(
+      (acc, conf) => deepmerge(acc, conf),
+      firstConfig
+    );
     const cspDirectives = new CspDirectives();
 
     // combining `default` directive configurations