# CVE-2019-16780: Stored cross-site scripting (XSS) in WordPress block editor

> Authenticated low-privilege users can inject JavaScript into the WordPress block editor, leading to XSS when admins view the post.

- **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A: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:** Yes
- **Published:** 26 Dec 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-16780, GHSA-x3wp-h3qx-9w94, UBUNTU-CVE-2019-16780

## What is CVE-2019-16780?

CVE-2019-16780 is a medium-severity cross-site scripting vulnerability in Debian Debian Linux, published on 26 Dec 2019. 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 users with lower privileges (like contributors) can inject JavaScript code in the block editor using a specific payload, which is executed within the dashboard. This can lead to XSS if an admin opens the post in the editor. Execution of this attack does require an authenticated user. This has been patched in WordPress 5.3.1, along with all the previous WordPress versions from 3.7 to 5.3 via a minor release. Automatic updates are enabled by default for minor releases and we strongly recommend that you keep them enabled.

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

## Which versions are affected by CVE-2019-16780?

It affects 2 products.


Products: Debian Debian Linux, Wordpress Wordpress.

## How do I fix CVE-2019-16780?

Upgrade to a fixed version.

## Is CVE-2019-16780 being exploited?

There is no known exploitation of CVE-2019-16780 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-16780 and fix it if it is affected.

What it is: CVE-2019-16780 is a medium-severity cross-site scripting vulnerability in Debian Debian Linux, published on 26 Dec 2019. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-16780 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2019-16780/ (Markdown: https://insights.sbomify.com/CVE-2019-16780/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-16780
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-16780
- OSV: https://osv.dev/vulnerability/CVE-2019-16780

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-16780/
Summaries are generated and may contain mistakes; the official description above is the record.