CVE-2025-66520 Foxit pdfonline.foxit.com Stored Cross-Site Scripting in Portfolio SVG Handling

Medium 6.3 Published 19 Dec 2025 Updated 19 Dec 2025

Attackers can execute arbitrary JavaScript in victims' browsers via malicious SVG files in the Portfolio feature of Foxit PDF Editor Cloud.

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: None listed

What is CVE-2025-66520?

CVE-2025-66520 is a medium-severity cross-site scripting vulnerability in pdfonline.foxit.com, published on 19 Dec 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

A stored cross-site scripting (XSS) vulnerability exists in the Portfolio feature of the Foxit PDF Editor cloud (pdfonline.foxit.com). User-supplied SVG files are not properly sanitized or validated before being inserted into the HTML structure. As a result, embedded HTML or JavaScript within a crafted SVG may execute whenever the Portfolio file list is rendered.

Weakness: CWE-79

Which versions are affected by CVE-2025-66520?

It affects 1 product.

Products include Foxit Pdf Editor Cloud.

How do I fix CVE-2025-66520?

No fix has been published for CVE-2025-66520 yet. Limit exposure of the affected software until one is available.

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-2025-66520 being exploited?

There is no known exploitation of CVE-2025-66520 in the wild and no public exploit code.

Sources

Also known as GHSA-fggr-pw4j-mqwr.