# CVE-2026-8839: MapPress Maps for WordPress <= 2.96.6 - Unauthenticated Insecure Direct Object Reference via REST API Endpoints

> Unauthenticated attackers can read sensitive map data, while authenticated users can modify or delete any map due to missing ownership checks in REST API endpoints.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Jun 2026
- **Updated:** 6 Jun 2026
- **Also known as:** GHSA-4m8c-59q5-hc8f

## What is CVE-2026-8839?

CVE-2026-8839 is a medium-severity missing authorization vulnerability in chrisvrichardson MapPress Maps for WordPress, published on 6 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The MapPress Maps for WordPress plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in all versions up to, and including, 2.96.6. This is due to missing ownership verification in the REST API routes registered via `Mappress_Api::rest_api_init()`, where the GET `/wp-json/mapp/v1/maps/{mapid}` endpoint uses `'permission_callback' => '__return_true'` and the write endpoints (POST update, DELETE, PATCH mutate, POST clone, POST empty_trash) only check the generic `edit_posts` capability without confirming that the requester owns the targeted map — a gap that is not compensated at the model layer, as `Mappress_Map::get()`, `save()`, `delete()`, `mutate()`, and `empty_trash()` all operate on any caller-supplied map ID without an ownership check. This makes it possible for unauthenticated attackers to read sensitive map data — including POI titles, addresses, coordinates, and body content — for any map on the site by enumerating map IDs, and for authenticated attackers with Contributor-level access and above to modify, delete, trash/restore, or clone any map regardless of its author.

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

## Which versions are affected by CVE-2026-8839?


## How do I fix CVE-2026-8839?

No fix has been published for CVE-2026-8839 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8839 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8839 exists.

Public exploit code:

- WordPress MapPress Maps <= 2.96.6 - Unauthenticated IDOR (nuclei): http/cves/2026/CVE-2026-8839.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8839 and fix it if it is affected.

What it is: CVE-2026-8839 is a medium-severity missing authorization vulnerability in chrisvrichardson MapPress Maps for WordPress, published on 6 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8839 exists.

Affected product: chrisvrichardson MapPress Maps for WordPress. 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-2026-8839/ (Markdown: https://insights.sbomify.com/CVE-2026-8839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8839
- OSV: https://osv.dev/vulnerability/CVE-2026-8839

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-8839/
Summaries are generated and may contain mistakes; the official description above is the record.