CVE-2026-55809 Flag attendance field - Critical - PHP object injection - SA-CONTRIB-2026-049
An attacker can exploit PHP object injection in the Drupal Flag attendance field plugin to potentially execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55809?
CVE-2026-55809 is a high-severity unsafe deserialization vulnerability in Drupal Flag attendance field, published on 10 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in Drupal Flag attendance field allows Object Injection. This issue affects Flag attendance field versions: from 0.0.0 to 1.2.
Weakness: CWE-915
Which versions are affected by CVE-2026-55809?
It affects 1 product.
Linux distribution packages (1)
drupal/flag_attendance_field Packagist:https://packages.drupal.org/8 | All versions | 1.2.0 |
Products include Flag Attendance Field Project Flag Attendance Field.
How do I fix CVE-2026-55809?
Upgrade to a fixed version.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-55809 being exploited?
There is no known exploitation of CVE-2026-55809 in the wild and no public exploit code.
Sources
Also known as DRUPAL-CONTRIB-2026-049, GHSA-66vp-2cwc-4pv3.