CVE-2019-16781 Stored cross-site scripting (XSS) in WordPress block editor

What is CVE-2019-16781?

CVE-2019-16781 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

In WordPress before 5.3.1, authenticated users with lower privileges (like contributors) can inject JavaScript code in the block editor, which is executed within the dashboard. It can lead to an admin opening the affected post in the editor leading to XSS.

Weakness: CWE-79

Which versions are affected by CVE-2019-16781?

It affects 2 products.

Products include Debian Debian Linux, Wordpress Wordpress.

How do I fix CVE-2019-16781?

Upgrade to a fixed version.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2019-16781 being exploited?

There is no known exploitation of CVE-2019-16781 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2019-16781, GHSA-pg4x-64rh-3c9v, UBUNTU-CVE-2019-16781.