libxml2 NULL ptr deref via XPath causes DoS
CVE-2025-49795 Published on June 16, 2025
Libxml: null pointer dereference leads to denial of service (dos)
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.
Vulnerability Analysis
CVE-2025-49795 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is a Dangling pointer Vulnerability?
The program dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid. When a program releases memory, but it maintains a pointer to that memory, then the memory might be re-allocated at a later time. If the original pointer is accessed to read or write data, then this could cause the program to read or modify data that is in use by a different function or process. Depending on how the newly-allocated memory is used, this could lead to a denial of service, information exposure, or code execution.
CVE-2025-49795 has been classified to as a Dangling pointer vulnerability or weakness.
Products Associated with CVE-2025-49795
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Vulnerable Packages
The following package name and versions may be associated with CVE-2025-49795
| Package Manager | Vulnerable Package | Versions | Fixed In |
|---|---|---|---|
| rubygems | nokogiri | < 1.18.9 | 1.18.9 |
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.