sh1zen WP Optimizer Plugin up to 2.5.0 on WordPress Subquery Detection Branch parse_key_compare_field sql injection

Summaryinfo

A vulnerability, which was classified as problematic, was found in sh1zen WP Optimizer Plugin up to 2.5.0. Affected by this issue is the function Query::parse_key_compare_field of the component Subquery Detection Branch. The manipulation of the argument s results in sql injection. This vulnerability is reported as CVE-2026-6295. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in sh1zen WP Optimizer Plugin up to 2.5.0. Affected is the function Query::parse_key_compare_field of the component Subquery Detection Branch. The manipulation of the argument s with an unknown input leads to a sql injection vulnerability. CWE is classifying the issue as CWE-89. The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The WP Optimizer plugin for WordPress is vulnerable to SQL Injection via the 's' parameter in all versions up to and including 2.5.0. This is due to an unsafe subquery-detection branch in the Query::parse_key_compare_field() method that, when the user-supplied value matches the regex ^[(\s]*SELECT\s+, wraps the value in parentheses and embeds it directly into the SQL string without any escaping or quoting. While the normal LIKE code path correctly uses esc_sql($wpdb->esc_like(...)) and wraps the value in single quotes, this branch completely bypasses those protections. Because the attack payload (SELECT ...) contains no single quotes, WordPress's wp_magic_quotes() provides no protection. This makes it possible for authenticated attackers with administrator-level access to inject arbitrary SQL subqueries — including time-based blind payloads — that can be used to extract sensitive information from the database.

The advisory is shared for download at wordfence.com. This vulnerability is traded as CVE-2026-6295 since 04/14/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Additional levels of successful authentication are required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/19/2026). The MITRE ATT&CK project declares the attack technique as T1505.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• sh1zen

Name

• WP Optimizer Plugin

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5.0

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
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Once again VulDB remains the best source for vulnerability data.

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