View online: https://www.drupal.org/sa-core-2026-002

Project: Drupal core [1] Date: 2026-April-15 Security risk: *Moderately critical* 14 ∕ 25 AC:Complex/A:Admin/CI:All/II:All/E:Theoretical/TD:Uncommon [2] Vulnerability: Gadget Chain

Affected versions: >= 8.0.0 < 10.5.9 || >= 10.6.0 < 10.6.7 || >= 11.0.0 < 11.2.11 || >= 11.3.0 < 11.3.7 CVE IDs: CVE-2026-6366 Description:  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(). There are no such known exploits in Drupal core.

Solution:  Install the latest version:

* If you use Drupal 10.5.x, update to Drupal 10.5.9 [3]. * If you use Drupal 10.6.x, update to Drupal 10.6.7 [4]. * If you use Drupal 11.2.x, update to Drupal 11.2.11 [5]. * If you use Drupal 11.3.x, update to Drupal 11.3.7 [6].

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 [7] and Drupal 9 [8] have both reached end-of-life.)

Reported By:  * Truong Le (hswww) [9] * menon [10] * t-chen [11]

Fixed By:  * Benji Fisher (benjifisher) [12] of the Drupal Security Team * cilefen (cilefen) [13] of the Drupal Security Team * Neil Drumm (drumm) [14] of the Drupal Security Team * Greg Knaddison (greggles) [15] of the Drupal Security Team * Lee Rowlands (larowlan) [16] of the Drupal Security Team * Dave Long (longwave) [17] of the Drupal Security Team * Drew Webber (mcdruid) [18] of the Drupal Security Team * Ra Mänd (ram4nd) [19], provisional member of the Drupal Security Team * Jess (xjm) [20] of the Drupal Security Team

Coordinated By:  * Greg Knaddison (greggles) [21] of the Drupal Security Team * Lee Rowlands (larowlan) [22] of the Drupal Security Team * Dave Long (longwave) [23] of the Drupal Security Team * Drew Webber (mcdruid) [24] of the Drupal Security Team * Juraj Nemec (poker10) [25] of the Drupal Security Team * Jess (xjm) [26] of the Drupal Security Team

Security issue: https://git.drupalcode.org/security/33-drupal-security/-/work_items/1 [27] ------------------------------------------------------------------------------ Contribution record [28]

[1] https://www.drupal.org/project/drupal [2] https://www.drupal.org/security-team/risk-levels [3] https://www.drupal.org/project/drupal/releases/10.5.9 [4] https://www.drupal.org/project/drupal/releases/10.6.7 [5] https://www.drupal.org/project/drupal/releases/11.2.11 [6] https://www.drupal.org/project/drupal/releases/11.3.7 [7] https://www.drupal.org/psa-2021-06-29 [8] https://www.drupal.org/psa-2023-11-01 [9] https://www.drupal.org/u/hswww [10] https://www.drupal.org/u/menon [11] https://www.drupal.org/u/t-chen [12] https://www.drupal.org/u/benjifisher [13] https://www.drupal.org/u/cilefen [14] https://www.drupal.org/u/drumm [15] https://www.drupal.org/u/greggles [16] https://www.drupal.org/u/larowlan [17] https://www.drupal.org/u/longwave [18] https://www.drupal.org/u/mcdruid [19] https://www.drupal.org/u/ram4nd [20] https://www.drupal.org/u/xjm [21] https://www.drupal.org/u/greggles [22] https://www.drupal.org/u/larowlan [23] https://www.drupal.org/u/longwave [24] https://www.drupal.org/u/mcdruid [25] https://www.drupal.org/u/poker10 [26] https://www.drupal.org/u/xjm [27] https://git.drupalcode.org/security/33-drupal-security/-/work_items/1 [28] https://new.drupal.org/contribution-record?source_link=https%3A//www.drupal....