# Wise Chat <= 3.4.5 - Reflected Cross-Site Scripting via Image Preparation Endpoint

- **ID:** WPSEC-2026-3134
- **Plugin:** Wise Chat (`wise-chat`), https://wordpress.org/plugins/wise-chat/
- **Affected versions:** all versions before 3.4.6
- **Fixed in:** 3.4.6 (Update to 3.4.6 or later.)
- **Severity:** Medium 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-11-14)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/wise-chat
- **Fix released:** 2026-11-13
- **Published:** 2026-11-14
- **URL:** https://wpsec.com/vuln/WPSEC-2026-3134/

## Description

The Wise Chat plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'data' parameter of the wise_chat_prepare_image_endpoint action in all versions up to, and including, 3.4.5, due to insufficient input validation and missing output escaping. The endpoint checked only that the value began with a 'data:image/gif;base64' prefix and then echoed the whole value back in a text/html response, and it had no nonce or XHR request check. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute in the browser of a chat user, granted they can trick that user into submitting a forged cross-site request, for example by visiting a malicious page.

## References

- https://wpsec.com/vuln/WPSEC-2026-3134/
- https://plugins.svn.wordpress.org/wise-chat/tags/3.4.6/
- https://wordpress.org/plugins/wise-chat/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-3134/

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.