CVE-2026-16965 in Solace Extra Plugin
Summary
by MITRE • 08/09/2026
The Solace Extra WordPress plugin before 1.6.1 does not perform capability or nonce checks in one of its AJAX actions, allowing any authenticated user such as a subscriber (and, via CSRF, any logged-in user) to update post meta on arbitrary posts and to deactivate the site's active templates.
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Analysis
by VulDB Data Team • 08/09/2026
The vulnerability in the Solace Extra WordPress plugin affects versions prior to 1.6.1 and represents a critical authorization flaw that undermines the security model of WordPress installations. This issue stems from insufficient capability and nonce validation within one of the plugin's AJAX endpoints, creating a pathway for unauthorized modifications that extends beyond typical user permissions. The flaw allows any authenticated user account, including low-privilege subscribers, to manipulate post metadata across arbitrary posts and deactivate active templates through a straightforward exploitation vector.
The technical implementation of this vulnerability resides in the plugin's handling of AJAX requests where proper WordPress security checks are omitted. Specifically, the affected AJAX action lacks both capability verification to ensure users possess appropriate permissions and nonce validation to prevent cross-site request forgery attacks. This absence means that any authenticated user session can submit malicious requests through CSRF techniques, effectively elevating the privileges of low-privilege accounts to perform actions typically restricted to administrators or editors. The vulnerability manifests as a direct consequence of inadequate input sanitization and access control implementation within the plugin's backend functionality.
The operational impact of this vulnerability extends beyond simple data modification capabilities, potentially enabling attackers to compromise entire WordPress installations through template deactivation and metadata manipulation. An attacker could exploit this flaw to disable active themes, rendering the website inaccessible to visitors while maintaining administrative control over content modifications. Additionally, the ability to update arbitrary post meta fields opens possibilities for injecting malicious content, manipulating search engine optimization parameters, or disrupting site functionality through strategic data corruption. The vulnerability's severity is amplified by its accessibility to any logged-in user, including those with minimal privileges, making it particularly dangerous in environments where subscriber accounts may be compromised.
This vulnerability aligns with CWE-863 (Incorrect Authorization) and represents a clear violation of the principle of least privilege that forms the foundation of secure application design. The flaw also maps to ATT&CK technique T1078 (Valid Accounts) as it leverages existing authenticated sessions without requiring additional credential compromise. Organizations should immediately implement mitigation strategies including upgrading to version 1.6.1 or later, which incorporates proper capability and nonce validation checks. Additionally, administrators should conduct thorough security audits of their WordPress installations, monitor for unauthorized template changes, and consider implementing additional access controls through security plugins or server-level configurations to prevent exploitation of similar vulnerabilities across other plugins and themes.