CVE-2025-49795 is a high-severity vulnerability identified in the libxml2 library used within Red Hat Enterprise Linux 10. The flaw is a NULL pointer dereference occurring during the processing of XPath XML expressions. Specifically, when libxml2 parses crafted malicious XML input containing XPath expressions, it can trigger an expired pointer dereference, causing the application or service relying on libxml2 to crash or become unresponsive. This results in a denial of service (DoS) condition. The vulnerability does not allow for code execution or data disclosure but impacts availability by crashing processes that parse XML data using libxml2. The CVSS v3.1 base score is 7.5, reflecting a network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), and high impact on availability (A:H). No known exploits are currently reported in the wild, and no patches or fixes have been linked yet. The vulnerability affects Red Hat Enterprise Linux 10, which is widely used in enterprise environments for servers and critical infrastructure. The root cause is improper handling of XPath expressions leading to dereferencing a NULL pointer, which is a common programming error that can be triggered remotely by sending malicious XML data to vulnerable services or applications using libxml2. This vulnerability is particularly relevant for applications that consume XML data from untrusted sources or expose XML processing functionality over the network.

For European organizations, the primary impact is a denial of service on systems running Red Hat Enterprise Linux 10 that utilize libxml2 for XML processing. This can disrupt critical services such as web servers, middleware, or enterprise applications that parse XML input, potentially leading to downtime and loss of availability. Industries relying heavily on Linux-based infrastructure, such as finance, telecommunications, government, and manufacturing, may experience operational interruptions. Although the vulnerability does not compromise confidentiality or integrity, the availability impact can affect business continuity and service level agreements. Attackers can exploit this remotely without authentication or user interaction, increasing the risk of automated or large-scale DoS attacks. The lack of known exploits currently reduces immediate risk, but the public disclosure means attackers could develop exploits rapidly. Organizations with exposed XML processing endpoints or those that accept XML input from external or untrusted sources are at higher risk. Given the critical role of Red Hat Enterprise Linux in European enterprise and public sector IT environments, this vulnerability could have widespread operational consequences if not addressed promptly.

1. Immediate mitigation should include restricting access to services that process XML input using libxml2 to trusted networks or authenticated users only, reducing exposure to untrusted inputs. 2. Monitor and filter incoming XML data to detect and block malformed or suspicious XPath expressions that could trigger the vulnerability. 3. Apply any available vendor patches or updates from Red Hat as soon as they are released; monitor Red Hat security advisories closely. 4. In the absence of patches, consider temporarily disabling or limiting XML processing features in affected applications or services if feasible. 5. Implement robust logging and monitoring to detect crashes or service disruptions indicative of exploitation attempts. 6. Conduct thorough testing of XML processing components in staging environments to identify and mitigate potential crash scenarios. 7. Employ network-level protections such as Web Application Firewalls (WAFs) with custom rules to block malicious XML payloads targeting XPath processing. 8. Educate development and operations teams about safe XML handling practices and the risks of processing untrusted XML data. These steps go beyond generic advice by focusing on controlling exposure, proactive detection, and operational adjustments until patches are available.