# CVE-2026-4066: Missing authorization in Smart Custom Fields

> Authenticated contributors can read private and draft posts from other authors due to missing capability checks in the Smart Custom Fields plugin.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Mar 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-v295-3wx7-pwm2

## What is CVE-2026-4066?

CVE-2026-4066 is a medium-severity missing authorization vulnerability in inc2734 Smart Custom Fields, published on 23 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Smart Custom Fields plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the relational_posts_search() function in all versions up to, and including, 5.0.6. This makes it possible for authenticated attackers, with Contributor-level access and above, to read private and draft post content from other authors via the smart-cf-relational-posts-search AJAX action. The function queries posts with post_status=any and returns full WP_Post objects including post_content, but only checks the generic edit_posts capability instead of verifying whether the requesting user has permission to read each individual post.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-4066?


## How do I fix CVE-2026-4066?

No fix has been published for CVE-2026-4066 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4066 being exploited?

There is no known exploitation of CVE-2026-4066 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4066 and fix it if it is affected.

What it is: CVE-2026-4066 is a medium-severity missing authorization vulnerability in inc2734 Smart Custom Fields, published on 23 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-4066 in the wild and no public exploit code.

Affected product: inc2734 Smart Custom Fields. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-4066/ (Markdown: https://insights.sbomify.com/CVE-2026-4066/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4066
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4066
- OSV: https://osv.dev/vulnerability/CVE-2026-4066

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4066/
Summaries are generated and may contain mistakes; the official description above is the record.