A recently disclosed security vulnerability in the All in One SEO (AIOSEO) WordPress plugin affects more than 3 million installations. The flaw allows authenticated users with Contributor-level access or higher to obtain a site's global AI access token. The AIOSEO development team has released a fix in version 4.9.3 of the plugin, and site owners are advised to update as soon as possible.
All In One SEO WordPress vulnerability: key details
Security company Wordfence reports that the issue stems from a missing permission check on a specific REST API endpoint. The affected endpoint, /aioseo/v1/ai/credits, returns information about a site's AI usage and remaining credits. Because the plugin did not restrict access correctly, lower-privileged users could access sensitive AI credentials.
Wordfence describes the issue as:
"Missing Authorization to Authenticated Contributor AI Access Token and Credit Disclosure."
According to its advisory, "authenticated attackers, with Contributor-level access and above," could disclose the global AI access token. The plugin uses this token to communicate with external AIOSEO AI services for content and media generation.
Key facts include:
- Plugin: All in One SEO (AIOSEO) for WordPress
- Affected versions: All versions up to and including 4.9.2
- Fixed version: 4.9.3, which adds hardened API route checks
- Installation base: 3+ million sites, per the official WordPress plugin listing
- Vulnerable endpoint:
/aioseo/v1/ai/creditswithout proper capability verification - Impact: Exposure of the global AI access token and AI credit information to contributor-level accounts
Background context on AIOSEO security issues
According to Wordfence, this AI token disclosure is one of several AIOSEO vulnerabilities reported in 2025. Its vulnerability database lists six separate issues for the plugin that year, including SQL injection, information disclosure, arbitrary media deletion, missing authorization checks, sensitive data exposure, and stored cross-site scripting.
Wordfence notes that several of these cases involved low-privilege roles, such as Contributor or Subscriber, accessing or modifying restricted data. The AI token issue follows the same pattern of insufficient permission enforcement on specific functions within the plugin.
For comparison, Wordfence data for 2025 records different counts for other major WordPress SEO plugins: Yoast SEO is listed with zero disclosed vulnerabilities, Rank Math with four, and Squirrly SEO with three during the same period.
Official sources and disclosures
Wordfence published its technical advisory on the AI token vulnerability in All in One SEO on its threat intelligence site, which describes the flaw in detail and provides remediation guidance.
The AIOSEO development team documents the fix on the official WordPress.org plugin page. Version 4.9.3 lists a security change that states: "Hardened API routes to prevent AI access token from being exposed." This is recorded in the plugin's WordPress.org page in the official plugin changelog.
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