---
title: "Deprecation: #95320 - Various method arguments in Authentication objects"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:deprecation-95320"
source: "Changelog/11.5/Deprecation-95320-VariousMethodArgumentsInAuthenticationObjects.rst"
typo3-version: "11.5"
typo3-major: 11
type: "deprecation"
issue: 95320
forge: "https://forge.typo3.org/issues/95320"
tags: ["Backend", "Frontend", "PHP-API", "FullyScanned", "ext:core"]
rendered: "2026-09-20T18:31:11+00:00"
---

# Deprecation: #95320 - Various method arguments in Authentication objects {#deprecation-95320}

See [forge#95320](https://forge.typo3.org/issues/95320)

## Description {#description}

The following methods of the classes
`\TYPO3\CMS\Core\Authentication\AbstractUserAuthentication` and
`\TYPO3\CMS\Core\Authentication\BackendUserAuthentication` have their
first argument been marked as deprecated:

-   `AbstractUserAuthentication->writeUC()`
-   `AbstractUserAuthentication->unpack_uc()`
-   `BackendUserAuthentication->backendCheckLogin()`

The following method has its third argument marked as deprecated:

-   `BackendUserAuthentication->isInWebMount()`

## Impact {#impact}

Calling these methods with an explicit argument of the deprecated
arguments given will trigger a PHP `E_USER_DEPRECATED` error.

## Affected installations {#affected-installations}

TYPO3 installations with custom extensions calling these methods
with the deprecated arguments which is highly unlikely.

## Migration {#migration}

Call `AbstractUserAuthentication->writeUC()` without a
method argument. If you need to explicitly set a custom UC value
which is not `AbstractUserAuthentication->uc`, you can set this via
`AbstractUserAuthentication->uc = $myValue;` in the
line before.

Call `AbstractUserAuthentication->unpack_uc()` without an
method argument. If you need to explicitly set a custom UC value
which is not `AbstractUserAuthentication->uc`, you can set this via
`AbstractUserAuthentication->uc = $myValue;` in the
line before.

Call `BackendUserAuthentication->backendCheckLogin()` without
an argument but wrap this call in a `try {} catch (\Throwable $e)` if
you need the old behavior and want to avoid a deprecation
message.

Call `BackendUserAuthentication->isInWebMount()` without the
third argument and check for the return value of being `null`
which is the equivalent of the expected `RuntimeException` being
thrown when the third argument was set to `true`.