View online: https://www.drupal.org/sa-contrib-2026-012
Project: Theme Negotiation by Rules [1]
Date: 2026-February-25
Security risk: *Moderately critical* 13 ∕ 25
AC:Basic/A:None/CI:None/II:Some/E:Theoretical/TD:All [2]
Vulnerability: Cross-site request forgery
Affected versions: <1.2.1
CVE IDs: CVE-2026-3211
Description:
This module allows site builders to create so-called "theme_rule" config
entities. These theme rules can render pages with different themes than the
default when certain conditions match.
The module uses simple GET request to disable or enable theme rules, which
allows attackers to disable or enable theme rules by tricking site
administrators to click on links.
This vulnerability is mitigated by the fact that an attacker must know the
machine name of the theme rule.
Solution:
Install the latest version:
* If you use the Theme Negotiation by Rules module, upgrade to Theme
Negotiation by Rules 1.2.1 [3].
Reported By:
* Juraj Nemec (poker10) [4] of the Drupal Security Team
Fixed By:
* Zoltan Attila Horvath (huzooka) [5]
* Juraj Nemec (poker10) [6] of the Drupal Security Team
Coordinated By:
* Damien McKenna (damienmckenna) [7] of the Drupal Security Team
* Greg Knaddison (greggles) [8] of the Drupal Security Team
* Juraj Nemec (poker10) [9] of the Drupal Security Team
* Jess (xjm) [10] of the Drupal Security Team
------------------------------------------------------------------------------
Contribution record [11]
[1] https://www.drupal.org/project/theme_rule
[2] https://www.drupal.org/security-team/risk-levels
[3] https://www.drupal.org/node/3575478
[4] https://www.drupal.org/u/poker10
[5] https://www.drupal.org/u/huzooka
[6] https://www.drupal.org/u/poker10
[7] https://www.drupal.org/u/damienmckenna
[8] https://www.drupal.org/u/greggles
[9] https://www.drupal.org/u/poker10
[10] https://www.drupal.org/u/xjm
[11]
https://new.drupal.org/contribution-record?source_link=https%3A//www.drupal…