From 9a9d62e046aa5c328b501ab26eadc9cc31f4ccb9 Mon Sep 17 00:00:00 2001
From: XananasX7 <security@example.com>
Date: Sun, 31 May 2026 04:38:55 +0000
Subject: [PATCH] fix(TaskProcessing): add allowed_classes to unserialize() in
 Manager cache

The availableTaskTypes cache stores serialized arrays containing
ShapeDescriptor objects, ShapeEnumValue objects, and EShapeType enum
values. The unserialize() call did not restrict which classes could
be instantiated.

Restrict deserialization to the three known types:
- OCP\TaskProcessing\ShapeDescriptor
- OCP\TaskProcessing\ShapeEnumValue
- OCP\TaskProcessing\EShapeType

This prevents PHP Object Injection if an attacker gains write access
to the distributed cache backend (e.g., a Redis instance without
authentication or with weak ACLs), which is a known real-world attack
vector in shared hosting and container environments.
---
 lib/private/TaskProcessing/Manager.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/private/TaskProcessing/Manager.php b/lib/private/TaskProcessing/Manager.php
index 6821aee65a002..024da47628954 100644
--- a/lib/private/TaskProcessing/Manager.php
+++ b/lib/private/TaskProcessing/Manager.php
@@ -939,7 +939,13 @@ public function getAvailableTaskTypes(bool $showDisabled = false, ?string $userI
 		if ($this->availableTaskTypes === null) {
 			$cachedValue = $this->distributedCache->get($cacheKey);
 			if ($cachedValue !== null) {
-				$this->availableTaskTypes = unserialize($cachedValue);
+				$this->availableTaskTypes = unserialize($cachedValue, [
+				'allowed_classes' => [
+					ShapeDescriptor::class,
+					ShapeEnumValue::class,
+					EShapeType::class,
+				],
+			]);
 			}
 		}
 		// Either we have no cache or showDisabled is turned on, which we don't want to cache, ever.