diff --git a/lib/Controller/WorkspaceController.php b/lib/Controller/WorkspaceController.php
index 52ea5e843e9..d83f9f365f6 100644
--- a/lib/Controller/WorkspaceController.php
+++ b/lib/Controller/WorkspaceController.php
@@ -132,7 +132,9 @@ public function publicFolder(string $shareToken, string $path = '/'): DataRespon
 			/** @psalm-suppress RedundantConditionGivenDocblockType */
 			if ($share->getPassword() !== null) {
 				$shareIds = $this->session->get('public_link_authenticated');
-				if ($share->getId() !== $shareIds && (is_array($shareIds) && !in_array($share->getId(), $shareIds, true))) {
+				$shareIds = is_array($shareIds) ? $shareIds : [$shareIds];
+
+				if (!in_array($share->getId(), $shareIds, true)) {
 					throw new ShareNotFound();
 				}
 			}
diff --git a/lib/Middleware/SessionMiddleware.php b/lib/Middleware/SessionMiddleware.php
index fa9d4255c55..b291d9a66fc 100644
--- a/lib/Middleware/SessionMiddleware.php
+++ b/lib/Middleware/SessionMiddleware.php
@@ -144,7 +144,9 @@ private function assertUserOrShareToken(ISessionAwareController $controller): vo
 
 			if ($share->getPassword() !== null) {
 				$shareIds = $this->session->get('public_link_authenticated');
-				if ($share->getId() !== $shareIds && (is_array($shareIds) && !in_array($share->getId(), $shareIds, true))) {
+				$shareIds = is_array($shareIds) ? $shareIds : [$shareIds];
+
+				if (!in_array($share->getId(), $shareIds, true)) {
 					throw new InvalidSessionException();
 				}
 			}
diff --git a/tests/unit/Middleware/SessionMiddlewareTest.php b/tests/unit/Middleware/SessionMiddlewareTest.php
new file mode 100644
index 00000000000..647a5c6843f
--- /dev/null
+++ b/tests/unit/Middleware/SessionMiddlewareTest.php
@@ -0,0 +1,117 @@
+<?php
+
+namespace OCA\Text\Tests;
+
+use OCA\Text\Controller\ISessionAwareController;
+use OCA\Text\Exception\InvalidSessionException;
+use OCA\Text\Middleware\SessionMiddleware;
+use OCA\Text\Service\DocumentService;
+use OCA\Text\Service\SessionService;
+use OCP\Files\Folder;
+use OCP\Files\IRootFolder;
+use OCP\IL10N;
+use OCP\IRequest;
+use OCP\ISession;
+use OCP\IUserSession;
+use OCP\Share\IManager;
+use OCP\Share\IShare;
+use Test\TestCase;
+
+class SessionMiddlewareTest extends TestCase {
+	private SessionMiddleware $middleware;
+	private IRequest $request;
+	private ISession $session;
+	private IUserSession $userSession;
+	private IRootFolder $rootFolder;
+	private IManager $shareManager;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->request = $this->createMock(IRequest::class);
+		$this->session = $this->createMock(ISession::class);
+		$this->userSession = $this->createMock(IUserSession::class);
+		$this->rootFolder = $this->createMock(IRootFolder::class);
+		$this->shareManager = $this->createMock(IManager::class);
+
+		$this->middleware = new SessionMiddleware(
+			$this->request,
+			$this->createMock(SessionService::class),
+			$this->createMock(DocumentService::class),
+			$this->session,
+			$this->userSession,
+			$this->rootFolder,
+			$this->shareManager,
+			$this->createMock(IL10N::class),
+		);
+	}
+
+	public function testUnauthenticatedAccessBlocked(): void {
+		$this->expectException(InvalidSessionException::class);
+
+		$share = $this->createPasswordProtectedShare('42');
+		$this->session->method('get')->with('public_link_authenticated')->willReturn(null);
+
+		$this->invokeMiddleware($share);
+	}
+
+	public function testAuthenticatedSingleIdAllowed(): void {
+		$share = $this->createPasswordProtectedShare('42');
+		$this->session->method('get')->with('public_link_authenticated')->willReturn('42');
+
+		$this->invokeMiddleware($share);
+		$this->assertTrue(true);
+	}
+
+	public function testAuthenticatedArrayAllowed(): void {
+		$share = $this->createPasswordProtectedShare('42');
+		$this->session->method('get')->with('public_link_authenticated')->willReturn(['40', '42', '44']);
+
+		$this->invokeMiddleware($share);
+		$this->assertTrue(true);
+	}
+
+	public function testWrongSingleIdBlocked(): void {
+		$this->expectException(InvalidSessionException::class);
+
+		$share = $this->createPasswordProtectedShare('42');
+		$this->session->method('get')->with('public_link_authenticated')->willReturn('99');
+
+		$this->invokeMiddleware($share);
+	}
+
+	public function testWrongArrayBlocked(): void {
+		$this->expectException(InvalidSessionException::class);
+
+		$share = $this->createPasswordProtectedShare('42');
+		$this->session->method('get')->with('public_link_authenticated')->willReturn(['10', '20', '30']);
+
+		$this->invokeMiddleware($share);
+	}
+
+	private function createPasswordProtectedShare(string $id): IShare {
+		$share = $this->createMock(IShare::class);
+		$share->method('getId')->willReturn($id);
+		$share->method('getPassword')->willReturn('password');
+		$share->method('getPermissions')->willReturn(\OCP\Constants::PERMISSION_READ);
+		$share->method('getShareOwner')->willReturn('owner');
+		$share->method('getAttributes')->willReturn(null);
+		return $share;
+	}
+
+	private function invokeMiddleware(IShare $share): void {
+		$this->request->method('getParam')->willReturnMap([
+			['documentId', null, 999],
+			['shareToken', null, 'token'],
+		]);
+		$this->userSession->method('getUser')->willReturn(null);
+		$this->shareManager->method('getShareByToken')->willReturn($share);
+
+		$folder = $this->createMock(Folder::class);
+		$folder->method('getFirstNodeById')->willReturn($this->createMock(\OCP\Files\File::class));
+		$this->rootFolder->method('getUserFolder')->willReturn($folder);
+
+		$controller = $this->createMock(ISessionAwareController::class);
+		self::invokePrivate($this->middleware, 'assertUserOrShareToken', [$controller]);
+	}
+}