CVE-2025-49795

A NULL pointer dereference vulnerability was found in libxml2 when processing XPath XML expressions. This flaw allows an attacker to craft a malicious XML input to libxml2, leading to a denial of service.

This vulnerability marked as Important rather than Moderate due to its triggerability through untrusted input and impact on availability in a widely-used XML processing library like libxml2, which is often embedded in system-level and server-side applications. Although it is "just" a NULL pointer dereference—typically classified as a DoS—the context significantly elevates its severity. libxml2 frequently operates in environments that parse external XML content, such as web services, security scanners, and document processors. A crafted XML exploiting malformed XPath in Schematron schemas can reliably crash the application without requiring special privileges or user interaction.

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 is either unavailable or does not meet Red Hat Product Security standards for usability, deployment, applicability, or stability.