# CVE-2026-87966: Easy Appointments 4.0 - 4.0.2.1 - Unauthenticated Arbitrary Appointment Modification and Deletion via IDOR

> Unauthenticated attackers can modify or delete arbitrary appointments in Easy Appointments due to missing authorization checks on the reservation endpoint.

- **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:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-52p7-4rrr-jvcv

## What is CVE-2026-87966?

CVE-2026-87966 is a medium-severity missing authorization vulnerability in Unknown Easy Appointments, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Easy Appointments WordPress plugin before 4.0.2.2 does not perform an ownership or authorization check on its unauthenticated appointment-reservation endpoint before updating an existing appointment identified by a request-supplied id, allowing unauthenticated attackers to overwrite, and through a follow-on cleanup delete, arbitrary appointments.

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

## Which versions are affected by CVE-2026-87966?


## How do I fix CVE-2026-87966?

No fix has been published for CVE-2026-87966 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-87966 being exploited?

There is no known exploitation of CVE-2026-87966 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87966 and fix it if it is affected.

What it is: CVE-2026-87966 is a medium-severity missing authorization vulnerability in Unknown Easy Appointments, published on 18 Sep 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-2026-87966 in the wild and no public exploit code.

Affected product: Unknown Easy 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-2026-87966/ (Markdown: https://insights.sbomify.com/CVE-2026-87966/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87966
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87966
- OSV: https://osv.dev/vulnerability/CVE-2026-87966

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-87966/
Summaries are generated and may contain mistakes; the official description above is the record.