diff --git a/typo3/sysext/install/Classes/Updates/BackendUserConfigurationUpdate.php b/typo3/sysext/install/Classes/Updates/BackendUserConfigurationUpdate.php
new file mode 100644
index 000000000000..4a368cd4c324
--- /dev/null
+++ b/typo3/sysext/install/Classes/Updates/BackendUserConfigurationUpdate.php
@@ -0,0 +1,141 @@
+<?php
+declare(strict_types = 1);
+
+namespace TYPO3\CMS\Install\Updates;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use TYPO3\CMS\Core\Database\ConnectionPool;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Update the backend user "uc" array to use arrays for its structure, as old TYPO3 versions sometimes used stdClasses
+ * @internal This class is only meant to be used within EXT:install and is not part of the TYPO3 Core API.
+ */
+class BackendUserConfigurationUpdate implements UpgradeWizardInterface
+{
+    /**
+     * @return string Unique identifier of this updater
+     */
+    public function getIdentifier(): string
+    {
+        return 'backendUsersConfiguration';
+    }
+
+    /**
+     * @return string Title of this updater
+     */
+    public function getTitle(): string
+    {
+        return 'Update backend user configuration array';
+    }
+
+    /**
+     * @return string Longer description of this updater
+     */
+    public function getDescription(): string
+    {
+        return 'The backend user "uc" array, which is persisted in the db, now only allows for'
+            . ' arrays inside its structure instead of stdClass objects.'
+            . ' Update the uc structure for all backend users.';
+    }
+
+    /**
+     * Checks if an update is needed
+     *
+     * @return bool Whether an update is needed (TRUE) or not (FALSE)
+     */
+    public function updateNecessary(): bool
+    {
+        $needsExecution = false;
+
+        foreach ($this->getAffectedBackendUsers() as $backendUser) {
+            $userConfig = $this->unserializeUserConfig($backendUser['uc']);
+
+            array_walk_recursive($userConfig, function (&$item) use (&$needsExecution) {
+                if ($item instanceof \stdClass) {
+                    $needsExecution = true;
+                }
+            });
+
+            if ($needsExecution) {
+                break;
+            }
+        }
+
+        return $needsExecution;
+    }
+
+    /**
+     * @return string[] All new fields and tables must exist
+     */
+    public function getPrerequisites(): array
+    {
+        return [
+            DatabaseUpdatedPrerequisite::class
+        ];
+    }
+
+    /**
+     * Performs the database update for be_users
+     *
+     * @return bool
+     */
+    public function executeUpdate(): bool
+    {
+        foreach ($this->getAffectedBackendUsers() as $backendUser) {
+            $userConfig = $this->unserializeUserConfig($backendUser['uc']);
+            array_walk_recursive($userConfig, function (&$item) {
+                if ($item instanceof \stdClass) {
+                    $item = json_decode(json_encode($item), true);
+                }
+            });
+
+            $this->updateBackendUser($backendUser['uid'], $userConfig);
+        }
+
+        return true;
+    }
+
+    private function unserializeUserConfig(string $userConfig)
+    {
+        return unserialize($userConfig, ['allowed_classes' => ['stdClass']]);
+    }
+
+    private function getAffectedBackendUsers(): iterable
+    {
+        $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
+            ->getQueryBuilderForTable('be_users');
+        $queryBuilder->getRestrictions()->removeAll();
+        $statement = $queryBuilder
+            ->select('uid', 'uc')
+            ->from('be_users')
+            ->where(
+                $queryBuilder->expr()->like(
+                    'uc',
+                    $queryBuilder->createNamedParameter(
+                        '%"stdClass"%'
+                    )
+                )
+            );
+
+        return $statement->execute();
+    }
+
+    private function updateBackendUser(int $userId, array $userConfig): void
+    {
+        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('be_users');
+        $connection->update('be_users', ['uc' => serialize($userConfig)], ['uid' => $userId]);
+    }
+}
diff --git a/typo3/sysext/install/ext_localconf.php b/typo3/sysext/install/ext_localconf.php
index 90162edfb660..f0afb737bb0a 100644
--- a/typo3/sysext/install/ext_localconf.php
+++ b/typo3/sysext/install/ext_localconf.php
@@ -68,6 +68,8 @@
     = \TYPO3\CMS\Install\Updates\PopulatePageSlugs::class;
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['ext/install']['update']['argon2iPasswordHashes']
     = \TYPO3\CMS\Install\Updates\Argon2iPasswordHashes::class;
+$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['ext/install']['update']['backendUsersConfiguration']
+    = \TYPO3\CMS\Install\Updates\BackendUserConfigurationUpdate::class;
 
 $iconRegistry = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Imaging\IconRegistry::class);
 $icons = [