# CVE-2026-15827: Missing authorization in GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor

> Unauthenticated attackers can retrieve private Mailchimp audience configuration data from WordPress sites using the GutenKit plugin.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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:** 23 Jul 2026
- **Updated:** 23 Jul 2026
- **Also known as:** GHSA-phq4-ggcm-gj84

## What is CVE-2026-15827?

CVE-2026-15827 is a medium-severity missing authorization vulnerability in ataurr GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The GutenKit Blocks plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the /wp-json/gutenkit/v1/mailchimp/get/lists and /wp-json/gutenkit/v1/mailchimp/get/interests REST API endpoints in versions up to, and including, 2.4.12. Both endpoints are registered with permission_callback => '__return_true', and their callbacks read the site's stored Mailchimp API key from the gutenkit_settings_list option and proxy Mailchimp audience/list, merge-field, interest-category, interest-name, and subscriber-count metadata back to the caller with no login, nonce, or capability check. This makes it possible for unauthenticated attackers to retrieve private Mailchimp audience configuration information from any site that has configured the GutenKit Mailchimp integration.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-15827?


## How do I fix CVE-2026-15827?

No fix has been published for CVE-2026-15827 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15827 being exploited?

There is no known exploitation of CVE-2026-15827 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15827 and fix it if it is affected.

What it is: CVE-2026-15827 is a medium-severity missing authorization vulnerability in ataurr GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-15827 in the wild and no public exploit code.

Affected product: ataurr GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor. 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-2026-15827/ (Markdown: https://insights.sbomify.com/CVE-2026-15827/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15827
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15827
- OSV: https://osv.dev/vulnerability/CVE-2026-15827

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-15827/
Summaries are generated and may contain mistakes; the official description above is the record.