CVE-2026-11977

WP Post Author <= 3.9.1 - Authenticated (Author+) SQL Injection

2026-08-04 19:33
Ryoma Nishioka

Strategic Overview

Status
Patched in 3.10.0
Affected Version
<= 3.9.1
CVSS
6.5Medium
Weakness type
CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CVE
CVE-2026-11977
View all WP Post Author – Author Box, Multiple Authors, Guest Authors & Custom Avatars vulnerabilities

At a glance

CVE-2026-11977 is a medium-severity Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in the WP Post Author WordPress plugin, affecting versions <= 3.9.1. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires an authenticated account at Author level or above. The issue is fixed in version 3.10.0; sites on affected versions should update now. Disclosed August 2026, reported by Ryoma Nishioka.

Vulnerability Overview

The WP Post Author – Author Box, Multiple Authors, Guest Authors & Custom Avatars plugin for WordPress is vulnerable to generic SQL Injection via the 'wpma_metabox_authors_list' parameter in all versions up to, and including, 3.9.1 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with author-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. Exploitation is a two-step chain: an attacker first saves a crafted guest-author token via the wpma_metabox_authors_list parameter during post creation or editing, then triggers the injection when any admin user loads the post list screen at /wp-admin/edit.php, causing the injected SQL result to be rendered in the Authors column.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

WP Post Author <= 3.9.1 carries this weakness at wpma_metabox_authors_list, and reaching it takes an account at Author level or above. SQL injection happens when request data is concatenated into a query instead of being bound as a parameter, letting an attacker change the structure of the statement rather than just its values.

A working injection can read any table the database user can see, which on a WordPress install means user records, password hashes and session or API secrets stored in options. For WP Post Author the fix is 3.10.0: builds <= 3.9.1 are affected, anything from 3.10.0 onward is not.

Remediation

Update to version 3.10.0, or a newer patched version

How WordSec helps

An attacker needs Author access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WP Post Author 3.10.0 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

Related records

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