# CVE-2026-6441: Canto <= 3.1.1 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Setting Modification

> Authenticated subscribers can arbitrarily modify or delete Canto plugin settings and cron schedules due to missing authorization checks.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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:** 17 Apr 2026
- **Updated:** 17 Apr 2026
- **Also known as:** GHSA-8pj7-rr49-2c47

## What is CVE-2026-6441?

CVE-2026-6441 is a medium-severity missing authorization vulnerability in flightbycanto Canto, published on 17 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Canto plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 3.1.1. This is due to the absence of any capability check or nonce verification in the updateOptions() function, which is exposed via two AJAX hooks: wp_ajax_updateOptions (class-canto.php line 231) and wp_ajax_fbc_updateOptions (class-canto-settings.php line 76). Both hooks are registered exclusively under the wp_ajax_ prefix (requiring only a logged-in user), with no call to current_user_can() or check_ajax_referer(). This makes it possible for authenticated attackers with subscriber-level access and above to arbitrarily modify or delete plugin options controlling cron scheduling behavior (fbc_duplicates, fbc_cron, fbc_schedule, fbc_cron_time_day, fbc_cron_time_hour, fbc_cron_start) and to manipulate or clear the plugin's scheduled WordPress cron event (fbc_scheduled_update).

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-6441?


## How do I fix CVE-2026-6441?

No fix has been published for CVE-2026-6441 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6441 being exploited?

There is no known exploitation of CVE-2026-6441 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6441 and fix it if it is affected.

What it is: CVE-2026-6441 is a medium-severity missing authorization vulnerability in flightbycanto Canto, published on 17 Apr 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-2026-6441 in the wild and no public exploit code.

Affected product: flightbycanto Canto. 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-2026-6441/ (Markdown: https://insights.sbomify.com/CVE-2026-6441/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6441
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6441
- OSV: https://osv.dev/vulnerability/CVE-2026-6441

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6441/
Summaries are generated and may contain mistakes; the official description above is the record.