# CVE-2016-20084: WordPress appointment-booking-calendar 1.1.24 Privilege Escalation XSS

> Unauthenticated attackers can inject persistent XSS payloads into calendar settings, leading to script execution and potential privilege escalation in the admin interface.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Jun 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-vqrm-v8pv-6pvf

## What is CVE-2016-20084?

CVE-2016-20084 is a medium-severity cross-site scripting vulnerability in dwbooster Appointment Booking Calendar, published on 15 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

WordPress appointment-booking-calendar 1.1.24 contains multiple privilege escalation vulnerabilities that allow unauthenticated attackers to modify calendar settings and inject persistent cross-site scripting payloads through the admin.php page parameters. Attackers can inject malicious JavaScript into the 'ict' and 'ics' options or the calendar 'name' parameter via GET requests to execute arbitrary scripts when the calendar is displayed or accessed in the administration interface.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2016-20084?


## How do I fix CVE-2016-20084?

No fix has been published for CVE-2016-20084 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-20084 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20084 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-20084 and fix it if it is affected.

What it is: CVE-2016-20084 is a medium-severity cross-site scripting vulnerability in dwbooster Appointment Booking Calendar, published on 15 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20084 exists.

Affected product: dwbooster Appointment Booking Calendar. 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-2016-20084/ (Markdown: https://insights.sbomify.com/CVE-2016-20084/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-20084
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-20084
- OSV: https://osv.dev/vulnerability/CVE-2016-20084

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-20084/
Summaries are generated and may contain mistakes; the official description above is the record.