Backdrop CMS Backdrop any version

jQuery before 3.4.0, as used in Drupal, Backdrop CMS, and other products, mishandles jQuery.extend(true, {}, ...) because of Object.prototype pollution. If an unsanitized source object contained an enumerable __proto__ property, it could extend the native Object.prototype.

Backdrop CMS 1.12.x before 1.12.8 and 1.13.x before 1.13.3 doesn't sufficiently filter output when displaying certain block labels created by administrators. An attacker could potentially craft a specialized label, then have an administrator execute scripting when administering a layout. (This issue is mitigated by the attacker needing permission to create custom blocks on the site, which is typically an administrative permission.)

Backdrop CMS before 1.27.3 and 1.28.x before 1.28.2 does not sufficiently sanitize field labels before they are displayed in certain places. This vulnerability is mitigated by the fact that an attacker must have a role with the "administer fields" permission.