CVE-2026-32777 Denial of service in libexpat

Medium 4.0 Published 16 Mar 2026 Updated 15 Oct 2026

An attacker can cause a denial of service via an infinite loop in libexpat when parsing malicious DTD content.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2026-32777?

CVE-2026-32777 is a medium-severity denial of service vulnerability in Libexpat Project Libexpat, published on 16 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

libexpat before 2.7.5 allows an infinite loop while parsing DTD content.

Weakness: CWE-835

Which versions are affected by CVE-2026-32777?

It affects 1 product.

Products include Libexpat Project Libexpat.

How do I fix CVE-2026-32777?

Upgrade to a fixed version.

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-2026-32777 being exploited?

There is no known exploitation of CVE-2026-32777 in the wild and no public exploit code.

All Libexpat Project Libexpat vulnerabilities

Sources

Also known as ALPINE-CVE-2026-32777, AZL-79859, BELL-CVE-2026-32777, DEBIAN-CVE-2026-32777, ECHO-1645-a8de-a79e, GHSA-9rpf-mhcj-gv7r and 3 more.