CVE-2025-59364 express-xss-sanitizer has an unbounded recursion depth
An attacker can cause a denial of service via unbounded recursion in the Express XSS Sanitizer library when processing JSON request bodies.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-59364?
CVE-2025-59364 is a medium-severity denial of service vulnerability in Express XSS Sanitizer, published on 14 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The express-xss-sanitizer (aka Express XSS Sanitizer) package through 2.0.0 for Node.js has an unbounded recursion depth in sanitize in lib/sanitize.js for a JSON request body.
Weakness: CWE-674
Which versions are affected by CVE-2025-59364?
2 open source packages ship an affected version, including express-xss-sanitizer.
| Package | Affected | Fixed in |
|---|---|---|
express-xss-sanitizer npm | All versions | 2.0.1 |
express-xss-sanitizer npm | All versions | 2.0.1 |
How do I fix CVE-2025-59364?
Upgrade express-xss-sanitizer to 2.0.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-59364 being exploited?
There is no known exploitation of CVE-2025-59364 in the wild and no public exploit code.
Sources
Also known as GHSA-hvq2-wf92-j4f3.