CVE-2026-55809
Description
The Flag attendance field module gives you the ability to add attendance by depending on [Flag module](https://www.drupal.org/project/flag). `flag_attendance_field` stores some data as PHP-serialized strings. In some situations, malicious data can be written directly to the field. This can lead to an object injection vulnerability when the data are unserialized. This vulnerability is mitigated by the fact that an attacker must have permission to edit a content entity with an attached `flag_attendance_field` field. In addition, the core JSON:API module must be enabled with the option "Accept all JSON:API create, read, update, and delete operations", which is not the default, or the attacker needs some other way to edit field values directly.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Packagist:https://packages.drupal.org/8 | drupal/flag_attendance_field | <1.2.0 | 1.2.0 |
References
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.