CVE-2026-78576 Overview
The Readabler plugin for WordPress contains an SQL injection vulnerability affecting all versions prior to 2.0.18. The flaw stems from insufficient escaping of user-supplied parameters and inadequate preparation of the underlying SQL query. Unauthenticated attackers can append additional SQL statements to existing queries to extract sensitive database contents. The vulnerability is classified under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command).
Critical Impact
Unauthenticated remote attackers can extract sensitive data — including user credentials, session tokens, and site configuration — from any WordPress site running a vulnerable Readabler installation.
Affected Products
- Readabler plugin for WordPress, all versions prior to 2.0.18
- WordPress sites with the Readabler accessibility plugin installed and activated
- Any hosting environment exposing the affected plugin endpoints to the public internet
Discovery Timeline
- 2026-08-25 - CVE-2026-78576 published to NVD
- 2026-08-26 - Last updated in NVD database
Technical Details for CVE-2026-78576
Vulnerability Analysis
The Readabler plugin fails to sanitize user-controlled input before incorporating it into an SQL query. The plugin also does not use parameterized queries or prepared statements through the WordPress $wpdb->prepare() API. This combination allows an attacker to break out of the intended query context and inject arbitrary SQL clauses.
The issue is exploitable without authentication over the network. Attackers can retrieve confidential data such as WordPress user records from wp_users, password hashes, session tokens, and API secrets stored in wp_options. Integrity and availability of the database are not directly impacted, but exposed credentials frequently enable follow-on account takeover.
Root Cause
The root cause is improper neutralization of special elements in SQL statements. A user-supplied parameter is concatenated into a raw SQL string without escaping or type casting. Because the plugin bypasses wpdb::prepare() and equivalent sanitization helpers such as esc_sql() and absint(), injected metacharacters like single quotes and UNION keywords are treated as SQL syntax.
Attack Vector
Exploitation requires only network access to a vulnerable endpoint exposed by the plugin. An attacker crafts an HTTP request containing SQL payloads in the vulnerable parameter and observes the response or timing characteristics. Techniques include UNION-based extraction to append attacker-controlled columns and boolean or time-based blind injection when responses do not directly echo query results. Refer to the Patchstack advisory and the Wordfence vulnerability analysis for endpoint-specific technical details.
Detection Methods for CVE-2026-78576
Indicators of Compromise
- HTTP requests to Readabler plugin endpoints containing SQL metacharacters such as ', ", --, /*, or keywords like UNION SELECT, SLEEP(, BENCHMARK(, and INFORMATION_SCHEMA.
- Unusually long query strings or POST bodies targeting /wp-content/plugins/readabler/ or associated admin-ajax.php actions.
- Web server logs showing repeated requests from a single source with incrementing payloads consistent with automated SQL injection tooling such as sqlmap.
- Database error messages or 500 responses correlated with the above request patterns.
Detection Strategies
- Inspect WordPress access logs for requests referencing Readabler AJAX handlers combined with SQL syntax tokens.
- Deploy web application firewall (WAF) rules that flag SQL injection signatures against WordPress plugin endpoints.
- Correlate anomalous outbound data volume from the database host with inbound requests to the plugin.
- Monitor for new administrator account creation or unexpected changes to wp_users and wp_usermeta following suspicious traffic.
Monitoring Recommendations
- Enable MySQL general or slow query logging temporarily during triage to identify malformed queries reaching the database.
- Alert on WordPress plugin file integrity changes and on Readabler versions below 2.0.18 across the estate.
- Track EPSS movement and public exploit availability for CVE-2026-78576 to prioritize remediation windows.
How to Mitigate CVE-2026-78576
Immediate Actions Required
- Update the Readabler plugin to version 2.0.18 or later on every WordPress site in scope.
- If patching is delayed, deactivate and remove the Readabler plugin until the update can be applied.
- Rotate WordPress administrator passwords, API keys, and session secrets on any site that exposed the vulnerable endpoint to the internet.
- Review database and web logs for evidence of exploitation across the disclosure window.
Patch Information
The vendor released a fix in Readabler version 2.0.18. Administrators should upgrade through the WordPress plugin dashboard or via WP-CLI using wp plugin update readabler. Confirm the installed version after upgrade and verify plugin functionality against site accessibility requirements.
Workarounds
- Restrict access to the affected plugin endpoints using WAF rules or IP allowlists until the patch is applied.
- Enforce request filtering that rejects SQL metacharacters on parameters consumed by the plugin.
- Place the WordPress site behind a reverse proxy that enforces schema validation on query and body parameters.
# Update Readabler to the patched version via WP-CLI
wp plugin update readabler --version=2.0.18
wp plugin list --name=readabler --fields=name,status,version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
