diff --git a/CHANGELOG.md b/CHANGELOG.md
index 47a2d32..63121f3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 [PyPI History](https://pypi.org/project/demisto-py/#history)
 
+## 3.2.xx
+* Updated custom request headers validation logic to handle "Cookie" headers.
+
 ## 3.2.14
 * Added support for Python versions 3.11 and 3.12.
 
diff --git a/demisto_client/__init__.py b/demisto_client/__init__.py
index ae8b5e1..10bbf59 100644
--- a/demisto_client/__init__.py
+++ b/demisto_client/__init__.py
@@ -19,7 +19,7 @@
     __version__ = 'dev'
 
 
-DEMISTO_HTTP_HEADERS_REGEX_PATTERN = r'^([\w-]+=[^=,\n]+)(,[\w-]+=[^=,\n]+)*$'
+DEMISTO_HTTP_HEADERS_REGEX_PATTERN = r'^(Cookie=[^,\n]+|[\w-]+=[^=,\n]+)(,(Cookie=[^,\n]+|[\w-]+=[^=,\n]+))*$'
 
 
 def configure(base_url=None, api_key=None, advanced_api_key=None, verify_ssl=None, proxy=None, username=None, password=None,
diff --git a/tests/mocks_test.py b/tests/mocks_test.py
index 4e92696..a311c45 100644
--- a/tests/mocks_test.py
+++ b/tests/mocks_test.py
@@ -721,6 +721,7 @@ def test_configure_client_invalid_additional_headers_form_env_var(self, mocker:
                 "Content-type=123",
                 {'Content-type': '123'}
             ),
+            
             (
                 "  ",
                 {}