Drupal core – Moderately critical – Gadget chain – SA-CORE-2026-006

SecurityVulns
Yanac

Project: Drupal coreDate: 2026-June-17Security risk: Moderately critical 14 ∕ 25 AC:Complex/A:Admin/CI:All/II:All/E:Theoretical/TD:UncommonVulnerability: Gadget chainAffected versions: <10.5.12 || >=10.6.0 <10.6.11 || >=11.2.0 <11.2.14 || >=11.3.0 <11.3.12 || 11.0.* || 11.1.*CVE IDs: CVE-2026-55804Description: Drupal core contains a chain of methods that could be exploitable when an insecure deserialization vulnerability exists on the site. This so-called “gadget chain” presents no direct threat, but is a vector that can be used to achieve remote code execution or SQL injection if the application deserializes untrusted data due to another vulnerability.
This issue is not directly exploitable.
This issue is mitigated by the fact that in order for it to be exploitable, a separate vulnerability must be present to allow an attacker to pass unsafe input to unserialize().Solution: Install the latest version:
Drupal 11

If you use Drupal 11.3.x, update to Drupal 11.3.12.
If you use Drupal 11.2.x, update to Drupal 11.2.14.

Drupal 10

If you use Drupal 10.6.x, update to Drupal 10.6.11.
If you use Drupal 10.5.x, update to Drupal 10.5.12.

Drupal 11.1.x, Drupal 11.0.x, Drupal 10.4.x, and below are end-of-life and do not receive security coverage. (Drupal 8 and Drupal 9 have both reached end-of-life.)Reported By: 
Michael Maturi (michaelmaturi)
Fixed By: 
Lee Rowlands (larowlan) of the Drupal Security Team
Drew Webber (mcdruid) of the Drupal Security Team
Mohit Aghera (mohit_aghera)
Coordinated By: 
Anna Kalata (akalata) of the Drupal Security Team
Benji Fisher (benjifisher) of the Drupal Security Team
cilefen (cilefen) of the Drupal Security Team
Greg Knaddison (greggles) of the Drupal Security Team
Lee Rowlands (larowlan) of the Drupal Security Team
Dave Long (longwave) of the Drupal Security Team
Drew Webber (mcdruid) of the Drupal Security Team
Juraj Nemec (poker10) of the Drupal Security Team
Jess (xjm) of the Drupal Security TeamSecurity advisoriesRead More