# CVE-2026-6723: Missing authorization in Simply Schedule Appointments

> Unauthenticated attackers can modify sensitive appointment fields, including payment status and assignments, due to missing authorization checks in the REST API.

- **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:** 10 Oct 2026
- **Updated:** 11 Oct 2026
- **Also known as:** GHSA-3ppx-frf5-28p4

## What is CVE-2026-6723?

CVE-2026-6723 is a medium-severity missing authorization vulnerability in croixhaug Simply Schedule Appointments, published on 10 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Incorrect Authorization in all versions up to, and including, 1.6.11.11. This is due to the appointment update REST API endpoint not restricting which fields can be modified by token-authenticated customers. This makes it possible for unauthenticated attackers to modify admin-controlled fields on that appointment, including faking payment confirmation, reassigning the appointment to another user, and changing the service type.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-6723?


## How do I fix CVE-2026-6723?

No fix has been published for CVE-2026-6723 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6723 being exploited?

There is no known exploitation of CVE-2026-6723 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6723 and fix it if it is affected.

What it is: CVE-2026-6723 is a medium-severity missing authorization vulnerability in croixhaug Simply Schedule Appointments, published on 10 Oct 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-2026-6723 in the wild and no public exploit code.

Affected product: croixhaug Simply Schedule Appointments. 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-2026-6723/ (Markdown: https://insights.sbomify.com/CVE-2026-6723/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6723
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6723
- OSV: https://osv.dev/vulnerability/CVE-2026-6723

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6723/
Summaries are generated and may contain mistakes; the official description above is the record.