CVE-2026-2127 in SiteOrigin Widgets Bundle Plugin
Summary
by MITRE • 02/18/2026
The SiteOrigin Widgets Bundle plugin for WordPress is vulnerable to unauthorized arbitrary shortcode execution in all versions up to, and including, 1.70.4. This is due to a missing capability check on the `siteorigin_widget_preview_widget_action()` function which is registered via the `wp_ajax_so_widgets_preview` AJAX action. The function only verifies a nonce (`widgets_action`) but does not check user capabilities. This makes it possible for authenticated attackers, with Subscriber-level access and above, to execute arbitrary shortcodes by invoking the `SiteOrigin_Widget_Editor_Widget` via the preview endpoint. The required nonce is exposed on the public frontend when the Post Carousel widget is present on a page, embedded in the `data-ajax-url` HTML attribute.
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Analysis
by VulDB Data Team • 02/18/2026
The vulnerability identified as CVE-2026-2127 resides within the SiteOrigin Widgets Bundle plugin for WordPress, affecting all versions through 1.70.4. This represents a critical authorization flaw that allows attackers to execute arbitrary shortcodes without proper capability verification. The vulnerability stems from the `siteorigin_widget_preview_widget_action()` function which handles preview operations through the `wp_ajax_so_widgets_preview` AJAX endpoint. The function's implementation fails to perform adequate user capability checks, relying solely on nonce validation which is insufficient for preventing unauthorized execution.
The technical flaw manifests through a missing capability check in the preview functionality, creating an authorization bypass that enables authenticated attackers with Subscriber-level privileges or higher to exploit the system. This vulnerability is particularly concerning because it leverages the exposed nonce mechanism that becomes accessible through the public frontend when the Post Carousel widget is present on a page. The nonce value is embedded within the `data-ajax-url` HTML attribute, making it readily available to any authenticated user who can view pages containing this widget.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with the ability to execute arbitrary shortcodes through the SiteOrigin_Widget_Editor_Widget preview endpoint. This capability allows for potential code injection, data manipulation, and further exploitation of the WordPress environment. The vulnerability is classified under CWE-863, which addresses "Incorrect Authorization," and aligns with ATT&CK technique T1078.004 for Valid Accounts, as it requires only subscriber-level access to exploit. Attackers can leverage this weakness to perform actions such as executing malicious shortcodes, accessing restricted content, or potentially establishing persistent access through the preview functionality.
Mitigation strategies for this vulnerability require immediate plugin updates to versions that address the capability check deficiency. System administrators should also implement network-level monitoring to detect unusual AJAX requests to the preview endpoint and consider restricting access to the preview functionality through firewall rules or additional authentication layers. The remediation process should include thorough review of all user roles and capabilities, ensuring that only authorized personnel can access the widget preview functionality. Additionally, organizations should conduct comprehensive security assessments of their WordPress installations to identify similar authorization flaws in other plugins or themes that may expose similar vulnerabilities through missing capability checks in AJAX endpoints.