CVE-2026-31819

Workarounds

If you cannot update Sylius immediately, copy the affected classes from vendor to your project's src/ directory, apply the fix, and override the service definitions.

Step 1 - CurrencySwitchController

Copy from vendor/sylius/sylius/src/Sylius/Bundle/ShopBundle/Controller/CurrencySwitchController.php to src/Controller/CurrencySwitchController.php and apply the following changes:

-namespace Sylius\Bundle\ShopBundle\Controller;
+namespace App\Controller;

 use Sylius\Component\Channel\Context\ChannelContextInterface;
 use Sylius\Component\Core\Currency\CurrencyStorageInterface;
 use Sylius\Component\Core\Model\ChannelInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\RouterInterface;

 final class CurrencySwitchController
 {
     public function __construct(
         private Environment $templatingEngine, // for 1.x version
         private CurrencyStorageInterface $currencyStorage,
         private ChannelContextInterface $channelContext,
+        private RouterInterface $router,
     ) {
     }

     public function switchAction(Request $request, string $code): Response
     {
         /** @var ChannelInterface $channel */
         $channel = $this->channelContext->getChannel();

         $this->currencyStorage->set($channel, $code);

-        return new RedirectResponse($request->headers->get('referer', $request->getSchemeAndHttpHost()));
+        return new RedirectResponse($this->router->generate('sylius_shop_homepage'));
     }
 }

Step 2 - ImpersonateUserController

Copy from vendor/sylius/sylius/src/Sylius/Bundle/AdminBundle/Controller/ImpersonateUserController.php to src/Controller/Admin/ImpersonateUserController.php and apply the following changes:

-namespace Sylius\Bundle\AdminBundle\Controller;
+namespace App\Controller\Admin;

 // ... (keep all existing use statements)

     public function impersonateAction(Request $request, string $username): Response
     {
         // ... (keep authorization check and impersonation logic)

         $this->addFlash($request, $username);

-        $redirectUrl = $request->headers->get(
-            'referer',
+        return new RedirectResponse(
             $this->router->generate('sylius_admin_customer_show', ['id' => $user->getId()])
         );
-
-        return new RedirectResponse($redirectUrl);
     }

Step 3 - StorageBasedLocaleSwitcher (only if you use locale_switcher: storage)

Note: Skip this step if you use the default locale_switcher: url mode.

Copy from vendor/sylius/sylius/src/Sylius/Bundle/ShopBundle/Locale/StorageBasedLocaleSwitcher.php to src/Locale/StorageBasedLocaleSwitcher.php and apply the following changes:

For Sylius 1.9 – 2.1.2:

-namespace Sylius\Bundle\ShopBundle\Locale;
+namespace App\Locale;

 use Sylius\Bundle\ShopBundle\Locale\LocaleSwitcherInterface;
 use Sylius\Component\Channel\Context\ChannelContextInterface;
 use Sylius\Component\Core\Locale\LocaleStorageInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Routing\RouterInterface;

 final class StorageBasedLocaleSwitcher implements LocaleSwitcherInterface
 {
     public function __construct(
         private LocaleStorageInterface $localeStorage,
         private ChannelContextInterface $channelContext,
+        private RouterInterface $router,
     ) {
     }

     public function handle(Request $request, string $localeCode): RedirectResponse
     {
         $this->localeStorage->set($this->channelContext->getChannel(), $localeCode);

-        return new RedirectResponse($request->headers->get('referer', $request->getSchemeAndHttpHost()));
+        return new RedirectResponse($this->router->generate('sylius_shop_homepage'));
     }
 }

For Sylius 2.1.3 and later:

In Sylius 2.1.3 the class was refactored to use UrlMatcherInterface. While this adds partial validation, it still passes the full referer URL to RedirectResponse, so the open redirect remains exploitable.

-namespace Sylius\Bundle\ShopBundle\Locale;
+namespace App\Locale;

 use Sylius\Bundle\ShopBundle\Locale\LocaleSwitcherInterface;
 use Sylius\Component\Channel\Context\ChannelContextInterface;
 use Sylius\Component\Core\Locale\LocaleStorageInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\Routing\Exception\ResourceNotFoundException;
-use Symfony\Component\Routing\Matcher\UrlMatcherInterface;
+use Symfony\Component\Routing\RouterInterface;

 final class StorageBasedLocaleSwitcher implements LocaleSwitcherInterface
 {
     public function __construct(
         private LocaleStorageInterface $localeStorage,
         private ChannelContextInterface $channelContext,
-        private ?UrlMatcherInterface $urlMatcher = null,
+        private RouterInterface $router,
     ) {
-        if (null === $this->urlMatcher) {
-            trigger_deprecation(
-                'sylius/shop-bundle',
-                '2.1',
-                'Not passing a "%s" to "%s" is deprecated and will be required in Sylius 3.0.',
-                UrlMatcherInterface::class,
-                self::class,
-            );
-        }
     }

     public function handle(Request $request, string $localeCode): RedirectResponse
     {
         $this->localeStorage->set($this->channelContext->getChannel(), $localeCode);
-        $url = $request->headers->get('referer', $request->getSchemeAndHttpHost());
-
-        if ($this->urlMatcher) {
-            try {
-                $this->urlMatcher->match($url);
-            } catch (ResourceNotFoundException) {
-                return new RedirectResponse($request->getSchemeAndHttpHost());
-            }
-        }
-
-        return new RedirectResponse($url);
+        return new RedirectResponse($this->router->generate('sylius_shop_homepage'));
     }
 }

Step 4 - Override the services

Add to config/services.yaml.

Sylius 1.x (1.9 – 1.14):

services:
    # ... your existing services ...

    sylius.controller.shop.currency_switch:
        class: App\Controller\CurrencySwitchController
        public: true
        arguments:
            $templatingEngine: '@twig'
            $currencyStorage: '@sylius.storage.currency'
            $channelContext: '@sylius.context.channel'
            $router: '@router'

    sylius.controller.shop.impersonate_user:
        class: App\Controller\Admin\ImpersonateUserController
        public: true
        arguments:
            $impersonator: '@sylius.admin.security.user_impersonator'
            $authorizationChecker: '@security.authorization_checker'
            $userProvider: '@sylius.admin_user_provider.email_or_name_based'
            $router: '@router'
            $authorizationRole: 'ROLE_ADMINISTRATION_ACCESS'

    # Only if you use locale_switcher: storage
    sylius.shop.locale_switcher:
        class: App\Locale\StorageBasedLocaleSwitcher
        public: false
        arguments:
            $localeStorage: '@sylius.storage.locale'
            $channelContext: '@sylius.context.channel'
            $router: '@router'

Sylius 2.x (2.0 – 2.1):

services:
    # ... your existing services ...

    sylius_shop.controller.currency_switch:
        class: App\Controller\CurrencySwitchController
        public: true
        arguments:
            $currencyStorage: '@sylius.storage.currency'
            $channelContext: '@sylius.context.channel'
            $router: '@router'

    sylius_admin.controller.impersonate_user:
        class: App\Controller\Admin\ImpersonateUserController
        public: true
        arguments:
            $impersonator: '@sylius_admin.security.shop_user_impersonator'
            $authorizationChecker: '@security.authorization_checker'
            $userProvider: '@sylius.shop_user_provider.email_or_name_based'
            $router: '@router'
            $authorizationRole: 'ROLE_ADMINISTRATION_ACCESS'

    # Only if you use locale_switcher: storage
    sylius_shop.locale_switcher:
        class: App\Locale\StorageBasedLocaleSwitcher
        public: false
        arguments:
            $localeStorage: '@sylius.storage.locale'
            $channelContext: '@sylius.context.channel'
            $router: '@router'

Step 5 - Clear cache

bin/console cache:clear

Customizing the redirect target

If you need a different redirect target, override the route definition with the _sylius.redirect attribute:

# config/routes/sylius_shop.yaml (AFTER the sylius_shop resource import)
sylius_shop_switch_currency:
    path: /{_locale}/switch-currency/{code}
    methods: [GET]
    defaults:
        _controller: sylius.controller.shop.currency_switch:switchAction
        _sylius:
            redirect: sylius_shop_product_index  # or any route name

Reporters

We would like to extend our gratitude to the following individuals for their detailed reporting and responsible disclosure of this vulnerability:

• Bartłomiej Nowiński (@bnBart)

For more information

If you have any questions or comments about this advisory:

• Open an issue in Sylius issues
• Email us at [email protected]

CurrencySwitchController::switchAction(), ImpersonateUserController::impersonateAction() and StorageBasedLocaleSwitcher::handle() use the HTTP Referer header directly when redirecting.

The attack requires the victim to click a legitimate application link placed on an attacker-controlled page. The browser automatically sends the attacker's site as the Referer, and the application redirects back to it. This can be used for phishing or credential theft, as the redirect originates from a trusted domain.

The severity varies by endpoint; public endpoints require no authentication and are trivially exploitable, while admin-only endpoints require an authenticated session but remain vulnerable if an admin follows a link from an external source such as email or chat.

Affected classes:

• CurrencySwitchController::switchAction() - public
• StorageBasedLocaleSwitcher::handle() - public, used in locale switching without having locale in the url
• ImpersonateUserController::impersonateAction() - admin-only

Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.

Kodem intelligence

The issue is fixed in versions: 1.9.12, 1.10.16, 1.11.17, 1.12.23, 1.13.15, 1.14.18, 2.0.16, 2.1.12, 2.2.3 and above.

1. What is CVE-2026-31819? CVE-2026-31819 is a medium-severity open redirect vulnerability in sylius/sylius (composer), affecting versions <= 1.9.11. It is fixed in 1.9.12, 1.10.16, 1.11.17, 1.12.23, 1.13.15, 1.14.18, 2.0.16, 2.1.12, 2.2.3. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
2. Which versions of sylius/sylius are affected by CVE-2026-31819? sylius/sylius (composer) versions <= 1.9.11 is affected.
3. Is there a fix for CVE-2026-31819? Yes. CVE-2026-31819 is fixed in 1.9.12, 1.10.16, 1.11.17, 1.12.23, 1.13.15, 1.14.18, 2.0.16, 2.1.12, 2.2.3. Upgrade to this version or later.
4. Is CVE-2026-31819 exploitable, and should I be worried? Whether CVE-2026-31819 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-31819 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-31819?
   • Upgrade sylius/sylius to 1.9.12 or later
   • Upgrade sylius/sylius to 1.10.16 or later
   • Upgrade sylius/sylius to 1.11.17 or later
   • Upgrade sylius/sylius to 1.12.23 or later
   • Upgrade sylius/sylius to 1.13.15 or later
   • Upgrade sylius/sylius to 1.14.18 or later
   • Upgrade sylius/sylius to 2.0.16 or later
   • Upgrade sylius/sylius to 2.1.12 or later
   • Upgrade sylius/sylius to 2.2.3 or later

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