# M Chart <= 2.4 - Unauthenticated Sensitive Information Exposure via Password-Protected Charts

- **ID:** WPSEC-2026-3124
- **Plugin:** M Chart (`m-chart`), https://wordpress.org/plugins/m-chart/
- **Affected versions:** all versions before 2.4.1
- **Fixed in:** 2.4.1 (Update to 2.4.1 or later.)
- **Severity:** Medium 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/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 2026-11-14)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/m-chart
- **Fix released:** 2026-11-13
- **Published:** 2026-11-14
- **URL:** https://wpsec.com/vuln/WPSEC-2026-3124/

## Description

The M Chart plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.4. The plugin ignores a chart's post password: the single chart page (the_content filter), the chart embed endpoint and the block REST endpoint /m-chart/v1/chart/<id> all render or return the chart without checking post_password_required(). This makes it possible for unauthenticated attackers to view the data, table and details of password-protected charts without knowing the password.

## References

- https://wpsec.com/vuln/WPSEC-2026-3124/
- https://plugins.svn.wordpress.org/m-chart/tags/2.4.1/
- https://wordpress.org/plugins/m-chart/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-3124/

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.