# CVE-2026-16557: Nimble Builder <= 3.3.8 - Subscriber+ Non-Public Content Disclosure via sek_get_nimble_content_for_seo_plugins

> Authenticated users can access non-public page-builder content due to missing authorization checks in the Nimble Page Builder WordPress 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:** 19 Sep 2026
- **Updated:** 19 Sep 2026
- **Also known as:** GHSA-4c39-75m8-74f3

## What is CVE-2026-16557?

CVE-2026-16557 is a medium-severity missing authorization vulnerability in Unknown Nimble Page Builder, published on 19 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Nimble Page Builder WordPress plugin through 3.3.8 does not perform an authorization check when returning page-builder content through an authenticated AJAX action, allowing any authenticated user (Subscriber+) to disclose the page-builder content of arbitrary non-public (draft, pending, private, scheduled) posts and pages.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-16557?


## How do I fix CVE-2026-16557?

No fix has been published for CVE-2026-16557 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16557 being exploited?

There is no known exploitation of CVE-2026-16557 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16557 and fix it if it is affected.

What it is: CVE-2026-16557 is a medium-severity missing authorization vulnerability in Unknown Nimble Page Builder, published on 19 Sep 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-2026-16557 in the wild and no public exploit code.

Affected product: Unknown Nimble Page Builder. 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-2026-16557/ (Markdown: https://insights.sbomify.com/CVE-2026-16557/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16557
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16557
- OSV: https://osv.dev/vulnerability/CVE-2026-16557

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16557/
Summaries are generated and may contain mistakes; the official description above is the record.