# Co-Authors Plus <= 4.1.2 - Authenticated (Contributor+) Missing Authorization to Guest Author Account Linking

- **ID:** WPSEC-2026-1744
- **Plugin:** Co-Authors Plus (`co-authors-plus`), https://wordpress.org/plugins/co-authors-plus/
- **Affected versions:** from 3.0 before 4.1.3
- **Fixed in:** 4.1.3 (Update to 4.1.3 or later.)
- **Severity:** Medium 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-862
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-10-27)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/co-authors-plus
- **Fix released:** 2026-10-26
- **Published:** 2026-10-27
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1744/

## Description

The Co-Authors Plus plugin for WordPress is vulnerable to unauthorized modification of data via the guest author 'linked account' field in all versions up to, and including, 4.1.2, due to a missing capability check when a guest author is saved. Guest authors use the default post capabilities, and the add-guest-author capability defaults to edit_posts. This makes it possible for authenticated attackers with Contributor-level access and above to create or edit a guest author linked to any WordPress user account. The guest author then replaces that user on bylines across the site, showing the attacker's chosen name, biography and website.

## References

- https://wpsec.com/vuln/WPSEC-2026-1744/
- https://plugins.svn.wordpress.org/co-authors-plus/tags/4.1.3/
- https://wordpress.org/plugins/co-authors-plus/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1744/

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.