CVE-2026-6653

A flaw was found in libxml2. A remote attacker can exploit a use-after-free vulnerability in the xmlParseInternalSubset function by providing maliciously crafted XML input. This improper handling of entity resolution can lead to a denial-of-service (DoS), making the affected system or application unavailable.

This Moderate impact use-after-free vulnerability in libxml2 can lead to a denial of service in Red Hat products that process untrusted XML input. In the worst-case scenario, a remote attacker is able to provide specially crafted XML, which, if parsed by an affected application, could cause the application to crash.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Updating to a fixed version of libxml2 (2.11.0 or later upstream, or a future RHEL errata) will fully resolve this issue.