# CVE-2016-20070: WordPress Booking Calendar Contact Form 1.0.23 Privilege Escalation Stored XSS

> Authenticated users can inject malicious scripts via plugin parameters, leading to arbitrary JavaScript execution in administrator browsers and potential privilege escalation.

- **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:** 15 Jul 2026
- **Also known as:** GHSA-fc95-cx3j-mr5q

## What is CVE-2016-20070?

CVE-2016-20070 is a medium-severity cross-site scripting vulnerability in dwbooster Booking Calendar Contact Form, 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 Booking Calendar Contact Form 1.0.23 contains privilege escalation and stored cross-site scripting vulnerabilities that allow authenticated users to modify plugin options and inject malicious scripts by failing to verify user privileges and sanitize input parameters. Attackers with subscriber-level accounts can inject XSS payloads through parameters like price, name, calendar_language, and email_confirmation_to_user via admin-ajax.php and admin.php endpoints to execute arbitrary JavaScript in administrator browsers.

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

## Which versions are affected by CVE-2016-20070?


## How do I fix CVE-2016-20070?

No fix has been published for CVE-2016-20070 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-20070 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20070 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-20070 and fix it if it is affected.

What it is: CVE-2016-20070 is a medium-severity cross-site scripting vulnerability in dwbooster Booking Calendar Contact Form, 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-2016-20070 exists.

Affected product: dwbooster Booking Calendar Contact Form. 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-2016-20070/ (Markdown: https://insights.sbomify.com/CVE-2016-20070/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-20070
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-20070
- OSV: https://osv.dev/vulnerability/CVE-2016-20070

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-20070/
Summaries are generated and may contain mistakes; the official description above is the record.