# Indieweb Post Kinds <= 3.7.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via Response Properties

- **ID:** WPSEC-2026-0777
- **Plugin:** Post Kinds (`indieweb-post-kinds`), https://wordpress.org/plugins/indieweb-post-kinds/
- **Affected versions:** all versions before 4.0.0
- **Fixed in:** 4.0.0 (Update to 4.0.0 or later.)
- **Severity:** Medium 6.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-10-11)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/indieweb-post-kinds
- **Fix released:** 2026-10-10
- **Published:** 2026-10-11
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0777/

## Description

The Post Kinds plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the citation author fields of the Response Properties metabox in all versions up to, and including, 3.7.3, due to insufficient input sanitization and output escaping. Author names are saved with sanitize_text_field(), which keeps quotes, and are then placed unescaped into HTML attributes of the generated h-card markup. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

## References

- https://wpsec.com/vuln/WPSEC-2026-0777/
- https://plugins.svn.wordpress.org/indieweb-post-kinds/tags/4.0.0/
- https://wordpress.org/plugins/indieweb-post-kinds/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0777/

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.