# Sprout Invoices – Client Invoicing & Estimates <= 20.8.18 - Authenticated (Contributor+) Sensitive Information Exposure via Client Associated Users Selector

- **ID:** WPSEC-2026-0852
- **Plugin:** Sprout Invoices – Client Invoicing & Estimates (`sprout-invoices`), https://wordpress.org/plugins/sprout-invoices/
- **Affected versions:** all versions before 20.8.19
- **Fixed in:** 20.8.19 (Update to 20.8.19 or later.)
- **Severity:** Medium 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)
- **Weakness:** CWE-200
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-13)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/sprout-invoices
- **Fix released:** 2026-10-12
- **Published:** 2026-10-13
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0852/

## Description

The Sprout Invoices plugin for WordPress is vulnerable to Sensitive Information Exposure via the client 'Associated Users' selector in all versions up to, and including, 20.8.18, due to the client submit meta box (shown on the client edit screen and returned by the 'sa_client_submit_metabox' AJAX action) listing every user on the site with their email address, without limiting the list to users the current user may associate. This makes it possible for authenticated attackers with contributor-level access and above, who can open the client edit screen, to get the email addresses and display names of all site users, administrators included.

## References

- https://wpsec.com/vuln/WPSEC-2026-0852/
- https://plugins.svn.wordpress.org/sprout-invoices/tags/20.8.19/
- https://wordpress.org/plugins/sprout-invoices/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0852/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.