diff --git a/NEWS b/NEWS
index 474db936ef15..549bb342c3f7 100644
--- a/NEWS
+++ b/NEWS
@@ -41,6 +41,8 @@ PHP                                                                        NEWS
   . Fix corruption in mod_mm. (ndossche)
   . Fixed bug GH-23043 (broken session id code can cause zend_mm_heap
     corrupted). (ndossche)
+  . Fixed bug GH-23061 (SessionHandler::create_sid() callback failure leaks
+    memory in debug build). (Lazizbek Ergashev)
 
 - Sockets:
   . Fixed various memory related issues in ext/sockets. (David Carlier)
diff --git a/ext/session/session.c b/ext/session/session.c
index 6380505ae951..a6b65ff57f18 100644
--- a/ext/session/session.c
+++ b/ext/session/session.c
@@ -145,6 +145,14 @@ static void php_rshutdown_session_globals(void) /* {{{ */
 			PS(mod)->s_close(&PS(mod_data));
 		} zend_end_try();
 	}
+	/* The user handler may not have closed the default handler it opened, e.g. because a pending
+	 * exception prevented its close callback from running at all */
+	if (PS(mod_user_is_open)) {
+		zend_try {
+			PS(default_mod)->s_close(&PS(mod_data));
+		} zend_end_try();
+		PS(mod_user_is_open) = false;
+	}
 	if (PS(id)) {
 		zend_string_release_ex(PS(id), 0);
 		PS(id) = NULL;
diff --git a/ext/session/tests/user_session_module/gh23061.phpt b/ext/session/tests/user_session_module/gh23061.phpt
new file mode 100644
index 000000000000..f3756e3462d0
--- /dev/null
+++ b/ext/session/tests/user_session_module/gh23061.phpt
@@ -0,0 +1,21 @@
+--TEST--
+GH-23061 (SessionHandler::create_sid() callback failure leaks memory in debug build)
+--EXTENSIONS--
+session
+--FILE--
+<?php
+class a extends SessionHandler {
+    function create_sid(): string {
+        return [3, 6];
+    }
+}
+$c = new a;
+session_set_save_handler($c);
+try {
+    session_start();
+} catch (Error $e) {
+    echo get_class($e), ": ", $e->getMessage(), "\n";
+}
+?>
+--EXPECT--
+Error: Session id must be a string