CVE-2026-10570 in Sympl Repeater Plugin
Summary
by MITRE • 07/08/2026
The Sympl Repeater for ACF and Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via ACF repeater field values in all versions up to, and including, 2.3. This is due to insufficient input sanitization and output escaping in the symp_arfe_replace_content() function, which uses str_replace() to substitute raw ACF field values (retrieved via get_field()) directly into Elementor-rendered HTML without any escaping. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 07/08/2026
The Sympl Repeater for ACF and Elementor plugin presents a critical stored cross-site scripting vulnerability that affects all versions up to and including 23. This vulnerability stems from inadequate input sanitization and output escaping mechanisms within the symp_arfe_replace_content() function. The flaw occurs when the plugin processes ACF repeater field values and directly injects them into Elementor-rendered HTML content without proper sanitization or escaping procedures. Attackers with author-level privileges or higher can exploit this weakness to inject malicious scripts that persist in the database and execute whenever affected pages are accessed by any user.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation. The core issue lies in the function's improper handling of user-provided content through the str_replace() operation, which processes raw ACF field data retrieved via get_field() without implementing adequate security measures. This approach creates a direct pathway for malicious input to be embedded into HTML output, effectively bypassing standard sanitization checks that should occur during content rendering. The vulnerability represents a classic case of insecure data handling where untrusted input flows directly into executable contexts.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with persistent access to compromised sites through authenticated sessions. Since the attack requires only author-level privileges, it can be exploited by users who already have significant control over content management systems. The stored nature of the XSS means that malicious scripts remain active until manually removed from the database, potentially affecting all users who view affected pages. This creates a persistent threat vector that can be leveraged for session hijacking, data exfiltration, or further exploitation of the WordPress environment.
Mitigation strategies should focus on implementing proper input validation and output escaping mechanisms throughout the plugin's codebase. The symp_arfe_replace_content() function must be modified to sanitize all ACF field values before inserting them into HTML contexts, utilizing appropriate escaping functions such as esc_html(), esc_attr(), or similar security measures. Security patches should enforce strict content validation rules that prevent the injection of executable scripts into database-stored content. Organizations should also consider implementing web application firewalls and monitoring systems to detect unusual content modifications, while maintaining regular updates to ensure all known vulnerabilities are addressed through proper patch management procedures.
This vulnerability demonstrates the importance of following established security frameworks such as the OWASP Top Ten and ATT&CK framework methodologies for preventing cross-site scripting attacks. The attack surface can be significantly reduced by implementing defense-in-depth strategies including input validation at multiple layers, output encoding for different contexts, and regular security assessments of third-party plugins. Additionally, the principle of least privilege should be enforced to minimize the potential impact of compromised accounts, ensuring that users with author-level access cannot perform actions that compromise system integrity. The vulnerability also highlights the need for comprehensive code reviews and automated security scanning processes specifically designed to identify insecure data handling patterns in WordPress plugin development environments.