CVE-2026-62059: Ultimate Member Plugin SQL Injection Flaw

CVE-2026-62059 Overview

CVE-2026-62059 is a Blind SQL Injection vulnerability in the Ultimate Member WordPress plugin. The flaw stems from improper neutralization of special elements used in an SQL command [CWE-89]. All versions of Ultimate Member up to and including 2.13.1 are affected.

An authenticated attacker with high privileges can inject crafted SQL fragments into vulnerable plugin inputs. The injection executes against the WordPress database and crosses a security scope, allowing data exposure beyond the attacker's authorized context. The vulnerability was published to the National Vulnerability Database (NVD) on October 1, 2026.

Critical Impact
Successful exploitation enables blind extraction of sensitive database contents, including WordPress user credentials, session tokens, and configuration data stored in wp_options.

Affected Products

Ultimate Member plugin for WordPress — versions through 2.13.1
WordPress sites running the vulnerable plugin with authenticated privileged users
Multi-site WordPress deployments sharing the ultimate-member plugin install

Discovery Timeline

2026-10-01 - CVE-2026-62059 published to NVD
2026-10-01 - Last updated in NVD database

Technical Details for CVE-2026-62059

Vulnerability Analysis

The Ultimate Member plugin fails to properly sanitize user-controlled input before concatenating it into SQL statements executed against the WordPress database. The vulnerability is classified as Blind SQL Injection, meaning the application does not return query results directly in HTTP responses. Attackers infer data by observing boolean responses or time-based delays.

The attack scope is marked as changed, indicating the injected query can access data belonging to a security authority different from the vulnerable component. In WordPress terms, injection in a plugin context exposes core tables such as wp_users, wp_usermeta, and wp_options. See the Patchstack SQL Injection Advisory for the vendor-coordinated disclosure.

Root Cause

The root cause is improper neutralization of special characters passed into dynamically constructed SQL queries. The plugin does not consistently use parameterized statements or the WordPress $wpdb->prepare() abstraction for all input paths. Single quotes, SQL comment sequences, and conditional operators pass through to the query layer unescaped.

Attack Vector

Exploitation requires network access and authenticated high-privilege credentials. The attacker submits payloads through the plugin's administrative or user-facing endpoints that reach vulnerable query logic. Boolean-based payloads toggle response characteristics, while time-based payloads use SLEEP() or BENCHMARK() to confirm injection. No user interaction is required to trigger the condition once the attacker is authenticated.

No public proof-of-concept exploit is listed in the NVD at the time of publication. The vulnerability is not present on the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-62059

Indicators of Compromise

Database query logs containing SQL meta-characters such as UNION SELECT, SLEEP(, BENCHMARK(, or stacked semicolons originating from Ultimate Member request handlers.
Unusual spikes in response time for authenticated requests to /wp-admin/admin-ajax.php with action parameters tied to the ultimate-member plugin.
Repeated requests from a single authenticated session iterating through numeric or character payloads consistent with blind extraction.
Access log entries showing privileged account activity against plugin endpoints outside normal administrative patterns.

Detection Strategies

Enable the MySQL/MariaDB general query log or slow query log and alert on queries referencing Ultimate Member tables with suspicious conditional expressions.
Deploy a web application firewall (WAF) rule set that identifies SQL injection signatures against WordPress plugin endpoints.
Correlate authenticated session identifiers with query volume anomalies to surface credential-abuse-driven injection attempts.

Monitoring Recommendations

Monitor WordPress audit logs for privileged user actions that touch ultimate-member administrative screens.
Track outbound DNS and HTTP egress from the WordPress host for out-of-band data exfiltration channels sometimes used in blind SQLi.
Alert on changes to wp_users and wp_usermeta rows made outside normal registration and profile update workflows.

How to Mitigate CVE-2026-62059

Immediate Actions Required

Inventory all WordPress sites and identify installations of the Ultimate Member plugin at version 2.13.1 or earlier.
Rotate credentials for all WordPress administrator and editor accounts after upgrading, assuming potential pre-patch exposure.
Restrict access to WordPress administrative URLs by IP allowlist or VPN until patching is complete.
Review database audit logs for the indicators listed above and treat matches as potential compromise.

Patch Information

Upgrade the Ultimate Member plugin to a version released after 2.13.1 that includes the vendor fix. Refer to the Patchstack SQL Injection Advisory for the fixed version reference and vendor coordination details. Apply the update through the WordPress plugin manager or WP-CLI across all affected sites.

Workarounds

Deactivate the Ultimate Member plugin until the patched version can be deployed, if business impact permits.
Reduce the number of accounts holding administrator or equivalent high-privilege roles to shrink the exploitable surface.
Deploy a virtual patch through a WAF that blocks SQL meta-characters on ultimate-member request parameters.
Enable multi-factor authentication for all privileged WordPress accounts to raise the cost of credential-based exploitation.

bash

# Upgrade Ultimate Member using WP-CLI
wp plugin update ultimate-member --version=latest
wp plugin list --name=ultimate-member --fields=name,status,version