# CVE-2026-1581 WordPress wpForo Forum Plugin is vulnerable to a high priority SQL Injection


## Overview

**Published:** 2026-02-19
**CVE-ID:** CVE-2026-1581
**CVSS:** 7.5
**Affected Plugin:** WordPress wpForo Forum Plugin
**Affected Versions:** <= 2.4.14
**Vulnerability Type:** High priority SQL Injection
**CWE:** CWE-89 Improper Neutralization of Special Elements used in an SQL Command.

## Description

The **wpForo Forum plugin** for WordPress is vulnerable to **time-based SQL Injection** via the **'wpfob'** parameter in **all versions** up to, and including, 2.4.14 due to **insufficient escaping** on the user supplied parameter and **lack of sufficient preparation** on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

## Patch And Commit Analysis


Based on Changelog of the product, we will compare between wpForo plugin version 2.4.14 (Patch) and 2.4.14 (Vulnerable) and analyze how developer patch and get into sink.


By comparing the source code of the vulnerable version with the patched release, we can pinpoint the exact **remediation strategy** applied by the **developers**. The core of the patch is located in the `includes/functions.php` file, where a new custom sanitization function named `wpforo_sanitize_orderby()`was introduced.

As anticipated for **ORDER BY SQL injection** vulnerabilities—where traditional **Prepared Statements** cannot be used for column names—the developers implemented a strict Whitelisting approach. The `wpforo_sanitize_orderby` function acts as a security gatekeeper:

- **Contextual Whitelists:** It defines an $allowed array containing explicitly permitted column names, meticulously categorized by their execution context (e.g., topics, posts, members, and search).

- **Input Validation:** Whenever the application processes the user-supplied wpfob parameter to sort results, it now routes the input through this function.

- **Neutralization:** The input is strictly validated against the predefined whitelist. If the injected payload does not match any of the allowed safe columns, it is immediately discarded and replaced with a safe default value.

This robust mechanism **effectively neutralizes** the vulnerability. Attackers can **no longer append arbitrary SQL functions** (such as `SLEEP()`) to the query, successfully mitigating the **Time-based SQL Injection** vector at the source.




The Patch also shows exact locations where the **sink** existed. The `clean_text_field()` function (which has no effect on SQLi errors in ORDER BY) has been completely **replaced** by the `wpforo_sanitize_orderby()` function with the **corresponding context**.

## Root Cause Analysis: Tracing from Sink to Source

To fully understand how this vulnerability is triggered, we will **trace** the **data flow** backward: starting **from the execution** point of the **SQL query (The Sink)** all the way up to where the user input is **initially processed (The Source)**.

**The Sink: Vulnerable SQL Execution (classes/Topics.php)**
The execution point of this **Time-based SQL Injection** lies within the `get_topics()` function in the `\classes\Topics` class.

When observing how the **SQL query** is constructed, we can see the **ORDER BY** clause being dynamically built:

$sql .= " ORDER BY " . str_replace( ',', ' ' . esc_sql( $order ) . ',', esc_sql( $orderby ) ) . " " . esc_sql( $order );

**Why is this vulnerable?**
The developer attempted to secure the input using **WordPress's native esc_sql()** function. However, `esc_sql()` is designed to escape string values by adding **slashes** to **quotes** (e.g., ' becomes \'). In **SQL syntax**, column names or functions within an **ORDER BY** clause are **not enclosed** in quotes. Therefore, an attacker can simply **inject an SQL function** like (SELECT SLEEP(5)) without using any quotes, entirely bypassing the `esc_sql()` protection. The query is then executed directly via `WPF()->db->get_results( $sql, ARRAY_A );`.


**The Data Flow: Variable Extraction**
Moving one step backward, we need to find where the $orderby variable originates within the `get_topics()` function.

At the beginning of this function, the $args array passed into the function is unpacked into local variables using PHP's `extract()` function:



This means that if the `$args` array contains a key named `orderby` (i.e., `$args['orderby'] = "malicious_payload")`, it will be **directly extracted** and **overwrite** the local `$orderby` variable, which is then passed down to the **vulnerable SQL string** concatenation.

**The Source: Unsafe Input Handling (wpforo.php)**
Finally, we trace back to where the `$args['orderby']` is initially populated from the **user's request**. This takes us to the core plugin file, specifically within the `init_current_object()` method of the wpforo class.

public function init_current_object() {
     $this->reset_current_object();
     $this->current_object['items_per_page'] = $this->post->get_option_items_per_page();
     $url = $this->current_url;
     $get = $this->GET;
          
     if( ! is_wpforo_page( $url ) ) return;
          
     $current_url = wpforo_get_url_query_vars_str( $url );
          
     $current_object = [];
     if( wpfkey( $get, 'wpfs' ) || wpfval( $get, 'foro' ) === 'search' ) $this->current_object['template'] = 'search';
     if( wpfval( $get, 'wpforo' ) || wpfval( $get, 'foro' ) ) {
          $request = ( wpfval( $get, 'wpforo' ) ) ? wpfval( $get, 'wpforo' ) : wpfval( $get, 'foro' );
          if( $request === 'page' ) $this->current_object['template'] = 'page';
     }

This method handles **routing and object initialization** based on the **requested template** (e.g., `recent`, `search`, `members`). When preparing the arguments to **fetch topics** for the `'recent'` template, we find the exact **entry point** of the user input:

$args['orderby'] = ( ! empty( WPF()->GET['wpfob'] ) ) ? sanitize_text_field( WPF()->GET['wpfob'] ) : 'modified';

**The Flaw at the Source:**
The application receives the wpfob parameter directly from the **user's GET request** `WPF()->GET['wpfob']`. It attempts to clean this input using `sanitize_text_field()`. While this function is excellent for **stripping HTML tags** and **preventing Cross-Site Scripting (XSS)**, it does absolutely nothing to **strip or neutralize SQL commands** like `SLEEP()`, `BENCHMARK()`, or `CASE WHEN`....

Consequently, the payload **travels securely from the user's browser**, passes through **inadequate sanitization** at the Source, flows through the `$args` array, and is ultimately **executed at the Sink**, resulting in a critical **Time-based SQL Injection**.

Based on all of it we have an attack flow :


## Proof Of Concept POC

Based on the source code analysis and data flow tracing, we can successfully exploit this Time-Based SQL Injection vulnerability by injecting payloads into the wpfob parameter.


First, we need to establish a baseline. Sending a standard `GET /community/recent/` request without any payload takes approximately 23 seconds to process on our specific test environment.


Next, we inject the `sleep(5)` payload via the wpfob parameter `(?wpfob=sleep(5))`. The server response time increases to roughly 29 seconds. This demonstrates a clear 5-to-6-second delay directly caused by our injected SQL command.


To definitively confirm the vulnerability and rule out random network latency, we increase the payload to `sleep(10)`. As expected, the response time jumps to 34 seconds `(baseline + 10 seconds)`. This precise control over the database's execution time conclusively proves the existence of the SQL Injection vulnerability.