# CVE-2026-86839: Bookly < 28.3 - Staff+ Appointment and Payment Disclosure, Modification and Deletion via IDOR

> Authenticated staff users can view, modify, and delete other staff members' appointments and payments due to missing ownership checks.

- **Severity:** Low 3.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/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:** 27 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-36wf-cx88-gfjh

## What is CVE-2026-86839?

CVE-2026-86839 is a low-severity missing authorization vulnerability in Unknown Online Scheduling and Appointment Booking System, published on 27 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The Online Scheduling and Appointment Booking System  WordPress plugin before 28.3 does not verify that appointment and payment records requested through its staff-role AJAX actions belong to the requesting staff member, allowing authenticated attackers with a staff-level account to view, modify and delete other staff members' appointments and payments, including the associated customer's personal information.

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

## Which versions are affected by CVE-2026-86839?


## How do I fix CVE-2026-86839?

No fix has been published for CVE-2026-86839 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86839 being exploited?

There is no known exploitation of CVE-2026-86839 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86839 and fix it if it is affected.

What it is: CVE-2026-86839 is a low-severity missing authorization vulnerability in Unknown Online Scheduling and Appointment Booking System, published on 27 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86839 in the wild and no public exploit code.

Affected product: Unknown Online Scheduling and Appointment Booking System. 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-2026-86839/ (Markdown: https://insights.sbomify.com/CVE-2026-86839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86839
- OSV: https://osv.dev/vulnerability/CVE-2026-86839

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86839/
Summaries are generated and may contain mistakes; the official description above is the record.