# CVE-2026-16957: Slim SEO < 4.9.11 - Contributor+ Arbitrary Post Meta Disclosure

> Contributors can read arbitrary post meta data, including private keys, from published posts they do not own due to insufficient authorization checks.

- **Severity:** Low 2.7 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Aug 2026
- **Updated:** 11 Aug 2026
- **Also known as:** GHSA-c8x4-7vmf-m6pv

## What is CVE-2026-16957?

CVE-2026-16957 is a low-severity missing authorization vulnerability in Unknown Slim SEO, published on 9 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The Slim SEO  WordPress plugin before 4.9.11 does not restrict a post-meta preview feature to posts the user is allowed to edit, verifying only read access, allowing users with the Contributor role to read arbitrary post meta, including protected and private keys, of published posts they do not own, including password-protected posts and posts of non-public post types.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-16957?


## How do I fix CVE-2026-16957?

No fix has been published for CVE-2026-16957 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16957 being exploited?

There is no known exploitation of CVE-2026-16957 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16957 and fix it if it is affected.

What it is: CVE-2026-16957 is a low-severity missing authorization vulnerability in Unknown Slim SEO, published on 9 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-16957 in the wild and no public exploit code.

Affected product: Unknown Slim SEO. 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-2026-16957/ (Markdown: https://insights.sbomify.com/CVE-2026-16957/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16957
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16957
- OSV: https://osv.dev/vulnerability/CVE-2026-16957

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16957/
Summaries are generated and may contain mistakes; the official description above is the record.