diff --git a/apps/files_external/lib/Controller/StoragesController.php b/apps/files_external/lib/Controller/StoragesController.php
index 21de089ab64..0d2560086f1 100644
--- a/apps/files_external/lib/Controller/StoragesController.php
+++ b/apps/files_external/lib/Controller/StoragesController.php
@@ -266,9 +266,14 @@ protected function updateStorageStatus(IStorageConfig &$storage, $testOnly = tru
 			);
 		} catch (\Exception $e) {
 			// FIXME: convert storage exceptions to StorageNotAvailableException
+			// Log the full exception server-side but do NOT expose the message to the
+			// client: exception messages from e.g. Guzzle contain resolved IP addresses,
+			// ports and cURL error details which can be used for internal network
+			// reconnaissance (information-disclosure / SSRF oracle).
+			$this->logger->logException($e, ['app' => 'files_external']);
 			$storage->setStatus(
 				StorageNotAvailableException::STATUS_ERROR,
-				\get_class($e).': '.$e->getMessage()
+				$this->l10n->t('Storage connection error. See server log for details.')
 			);
 		}
 	}
diff --git a/apps/files_external/tests/Controller/StoragesControllerTest.php b/apps/files_external/tests/Controller/StoragesControllerTest.php
index 3df57c9d04d..02841f9fbb3 100644
--- a/apps/files_external/tests/Controller/StoragesControllerTest.php
+++ b/apps/files_external/tests/Controller/StoragesControllerTest.php
@@ -446,6 +446,87 @@ public function testValidateStorage($backendValidate, $authMechValidate, $expect
 		}
 	}
 
+	/**
+	 * Verify that a generic \Exception thrown during updateStorageStatus does NOT leak
+	 * the raw exception class name or message into the JSON response's statusMessage
+	 * field (information-disclosure / SSRF-oracle fix).
+	 *
+	 * The vulnerability: the original catch block set statusMessage to
+	 *   get_class($e).': '.$e->getMessage()
+	 * which exposes resolved IP addresses, ports, and cURL error details to the
+	 * client when a Guzzle ConnectException is thrown.
+	 */
+	public function testUpdateStorageStatusDoesNotLeakExceptionDetailsInStatusMessage() {
+		$sensitiveMessage = 'cURL error 7: Failed to connect to 10.0.0.99 port 80: Connection refused';
+		$sensitiveClass   = 'GuzzleHttp\Exception\ConnectException';
+
+		$backend = $this->getMockBuilder('\OCP\Files\External\Backend\Backend')
+			->disableOriginalConstructor()
+			->getMock();
+		$backend->method('getStorageClass')
+			->willReturn('\OCA\Files_External\Lib\Storage\SMB');
+		$backend->method('getIdentifier')
+			->willReturn('identifier:\OCA\Files_External\Lib\Backend\SMB');
+		// Simulate a Guzzle-style exception thrown during manipulateStorageConfig
+		$backend->method('manipulateStorageConfig')
+			->willThrowException(new \RuntimeException($sensitiveMessage));
+
+		$authMech = $this->getAuthMechMock();
+
+		$storageConfig = new StorageConfig(1);
+		$storageConfig->setMountPoint('mount');
+		$storageConfig->setBackend($backend);
+		$storageConfig->setAuthMechanism($authMech);
+		$storageConfig->setBackendOptions([]);
+
+		$this->service->expects($this->once())
+			->method('getStorage')
+			->with(1)
+			->willReturn($storageConfig);
+
+		// Disable skipTest so the real exception path is exercised
+		\OC_Mount_Config::$skipTest = false;
+		$response = $this->controller->show(1);
+		\OC_Mount_Config::$skipTest = true;
+
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus());
+
+		$data = $response->getData();
+		$serialized = $data->jsonSerialize();
+
+		// The status must indicate error
+		$this->assertEquals(
+			StorageNotAvailableException::STATUS_ERROR,
+			$serialized['status'],
+			'Storage status must be STATUS_ERROR when a generic exception is thrown'
+		);
+
+		// The statusMessage MUST NOT contain the raw exception class name or message
+		$this->assertArrayHasKey('statusMessage', $serialized);
+		$statusMessage = $serialized['statusMessage'];
+
+		$this->assertStringNotContainsString(
+			$sensitiveMessage,
+			$statusMessage,
+			'statusMessage must not expose the raw exception message (network details leak)'
+		);
+		$this->assertStringNotContainsString(
+			$sensitiveClass,
+			$statusMessage,
+			'statusMessage must not expose the exception class name'
+		);
+		$this->assertStringNotContainsString(
+			'10.0.0.99',
+			$statusMessage,
+			'statusMessage must not expose internal IP addresses'
+		);
+		$this->assertStringNotContainsString(
+			'RuntimeException',
+			$statusMessage,
+			'statusMessage must not expose the exception class name'
+		);
+	}
+
 	protected function getNewStorageConfigMock($params) {
 		$backendMock = $this->getBackendMock(
 			$params['backendClass'] ?? '\Random\Missing\Class',
diff --git a/changelog/unreleased/41585 b/changelog/unreleased/41585
new file mode 100644
index 00000000000..3e0cb5d45c0
--- /dev/null
+++ b/changelog/unreleased/41585
@@ -0,0 +1,10 @@
+Security: Sanitize storage connection error messages returned to clients
+
+The external storage status handler returned raw exception messages
+including Guzzle cURL error details such as resolved IP addresses and
+port numbers in the JSON response. This allowed authenticated users to
+distinguish connection states and map internal network topology. The
+full exception is now logged server-side only; a generic message is
+returned to the client.
+
+https://github.com/owncloud/core/pull/41585