Flag attendance field security updates, in plain English

Flag attendance field

on drupal.org · 1 security update explained here

This module provides a way to track attendance for events or classes.

Below is every security update for Flag attendance field that this site has covered, newest first. Each one says who could exploit it, whether it applies to your site, how urgent it is, and what to tell your developer. If your site uses this module and you are not sure which version, that is the first question to ask whoever looks after it.

Flag attendance field

Critical · no install count published · SA-CONTRIB-2026-049 · on drupal.org · Week of 17 June 2026

An ordinary account on the site could write malicious data directly into an attendance field. This could allow them to view or alter any information on the site including the underlying code.

Who could do thisOnly someone with a login on your site.
Does it apply to youA site is affected if a person has access rights to edit a piece of content with an attendance field and the site allows full edit access through a data feed or another direct method.
Has it been used in attacksNo sign of it.
How urgentDrupal rates this critical. Cyber Essentials expects a fix within 14 days. Do it this week.

Tell your developerUpdate Flag attendance field to 8.x-1.2.

For developers: what the fix changed

The fix prevents PHP object injection by passing an array with allowed_classes set to false as the second argument to unserialize in FlagAttendanceFormatter.php and FlagAttendanceWidget.php.

8.x-1.1 to 8.x-1.2 1 commit, 2 files.

src/Plugin/Field/FieldFormatter/FlagAttendanceFormatter.php +1 −1 fix
src/Plugin/Field/FieldWidget/FlagAttendanceWidget.php +1 −1 fix

Full diff, 8.x-1.1 to 8.x-1.2

The comparison is against the release immediately before the fix. If your site is on an older release, more will have changed.

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Flag attendance field

Flag attendance field

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