diff --git a/session_db/pg_session_store.py b/session_db/pg_session_store.py
index ad47eb4fec0..4abdd1e3bb8 100644
--- a/session_db/pg_session_store.py
+++ b/session_db/pg_session_store.py
@@ -2,6 +2,8 @@
 # @author Nicolas Seinlet
 # Copyright (c) ACSONE SA 2022
 # @author Stéphane Bidoul
+import base64
+import binascii
 import json
 import logging
 import os
@@ -66,6 +68,7 @@ def __init__(self, uri, session_class=None):
         self._cr = None
         self._open_connection()
         self._setup_db()
+        self.prefix_binary = "base64::"
 
     def __del__(self):
         self._close_connection()
@@ -108,7 +111,8 @@ def _setup_db(self):
     @with_lock
     @with_cursor
     def save(self, session):
-        payload = json.dumps(dict(session))
+        json_session = self.session_to_str(dict(session))
+        payload = json.dumps(json_session)
         self._cr.execute(
             """
                 INSERT INTO http_sessions(sid, write_date, payload)
@@ -131,6 +135,7 @@ def get(self, sid):
         self._cr.execute("SELECT payload FROM http_sessions WHERE sid=%s", (sid,))
         try:
             data = json.loads(self._cr.fetchone()[0])
+            data = self.str_to_session(data)
         except Exception:
             return self.new()
 
@@ -149,6 +154,43 @@ def vacuum(self, max_lifetime=http.SESSION_LIFETIME):
             (f"{max_lifetime} seconds",),
         )
 
+    def _traverse_and_convert(self, data_node, conversion_func):
+        """
+        Recursively applies a conversion function to all elements in dicts and lists.
+        """
+        if isinstance(data_node, dict):
+            return {
+                self._traverse_and_convert(
+                    key, conversion_func
+                ): self._traverse_and_convert(value, conversion_func)
+                for key, value in data_node.items()
+            }
+        if isinstance(data_node, list):
+            return [
+                self._traverse_and_convert(item, conversion_func) for item in data_node
+            ]
+
+        return conversion_func(data_node)
+
+    def session_to_str(self, data):
+        def convert(value):
+            if isinstance(value, bytes):
+                return self.prefix_binary + base64.b64encode(value).decode("utf-8")
+            return value
+
+        return self._traverse_and_convert(data, convert)
+
+    def str_to_session(self, data):
+        def convert(value):
+            if isinstance(value, str) and value.startswith(self.prefix_binary):
+                try:
+                    return base64.b64decode(value[len(self.prefix_binary):], validate=True)
+                except (ValueError, TypeError, binascii.Error):
+                    return value
+            return value
+
+        return self._traverse_and_convert(data, convert)
+
 
 _original_session_store = http.root.__class__.session_store
 
diff --git a/session_db/tests/test_pg_session_store.py b/session_db/tests/test_pg_session_store.py
index 1bd0eb49ca2..75532268345 100644
--- a/session_db/tests/test_pg_session_store.py
+++ b/session_db/tests/test_pg_session_store.py
@@ -1,3 +1,4 @@
+import base64
 from unittest import mock
 
 import psycopg2
@@ -92,3 +93,46 @@ def test_make_postgres_uri(self):
         assert "postgres://test:PASSWORD@localhost:5432/test" == _make_postgres_uri(
             **connection_info
         )
+
+    def test_binary_serialization_roundtrip(self):
+        """Ensures binary data is safely serialized to a base64 string
+        and accurately deserialized back to bytes."""
+        original_data = {
+            "normal_text": "test",
+            "binary_data": b"Test binary",
+        }
+        serialized = self.session_store.session_to_str(original_data)
+        expected_b64 = base64.b64encode(b"Test binary").decode("utf-8")
+        self.assertEqual(
+            serialized["binary_data"],
+            f"base64::{expected_b64}",
+            "Binary data should be serialized with the configured prefix.",
+        )
+        self.assertEqual(serialized["normal_text"], "test")
+
+        deserialized = self.session_store.str_to_session(serialized)
+        self.assertEqual(deserialized["binary_data"], b"Test binary")
+        self.assertIsInstance(deserialized["binary_data"], bytes)
+
+    def test_recursive_traversal(self):
+        """Verifies that base64 serialization works inside nested structures."""
+        data = {
+            "list_of_data": [b"binary_in_list", "100", {"deep_key": b"deep_binary"}]
+        }
+        serialized = self.session_store.session_to_str(data)
+        self.assertTrue(serialized["list_of_data"][0].startswith("base64::"))
+        self.assertTrue(
+            serialized["list_of_data"][2]["deep_key"].startswith("base64::")
+        )
+
+        result = self.session_store.str_to_session(serialized)
+        self.assertEqual(result["list_of_data"][0], b"binary_in_list")
+        self.assertEqual(result["list_of_data"][1], "100")
+        self.assertEqual(result["list_of_data"][2]["deep_key"], b"deep_binary")
+
+    def test_invalid_base64_fallback(self):
+        """Failsafe: Invalid base64 strings with the exact prefix must return
+        the original string without crashing the session load."""
+        invalid_data = {"bad_binary": "base64::TESTS_INVALID_@#$"}
+        result = self.session_store.str_to_session(invalid_data)
+        self.assertEqual(result["bad_binary"], "base64::TESTS_INVALID_@#$")