# CVE-2026-87891: Rox Appointment Booking < 1.2.0 - Unauthenticated Holiday Schedule Modification via REST API

> Unauthenticated attackers can modify holiday schedules in the Rox Appointment Booking plugin, disrupting booking availability.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Sep 2026
- **Updated:** 12 Sep 2026
- **Also known as:** GHSA-82fg-m2x5-cqp7

## What is CVE-2026-87891?

CVE-2026-87891 is a medium-severity missing authorization vulnerability in Unknown Rox Appointment Booking, published on 12 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Rox Appointment Booking  WordPress plugin before 1.2.0 does not perform any capability or authorization check when saving its holiday schedule, allowing unauthenticated attackers to overwrite the dates the booking system treats as unavailable, which can block legitimate bookings or open dates the site owner intended to keep closed.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-87891?


## How do I fix CVE-2026-87891?

No fix has been published for CVE-2026-87891 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-87891 being exploited?

There is no known exploitation of CVE-2026-87891 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87891 and fix it if it is affected.

What it is: CVE-2026-87891 is a medium-severity missing authorization vulnerability in Unknown Rox Appointment Booking, published on 12 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-2026-87891 in the wild and no public exploit code.

Affected product: Unknown Rox Appointment Booking. 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-2026-87891/ (Markdown: https://insights.sbomify.com/CVE-2026-87891/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87891
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87891
- OSV: https://osv.dev/vulnerability/CVE-2026-87891

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-87891/
Summaries are generated and may contain mistakes; the official description above is the record.