NULL Pointer Dereference allows attackers to cause a denial of service (or application crash). This only applies when lxml is used together with libxml2 2.9.10 through 2.9.14. libxml2 2.9.9 and earlier are not affected. It allows triggering crashes through forged input data, given a vulnerable code sequence in the application. The vulnerability is caused by the iterwalk function (also used by the canonicalize function). Such code shouldn't be in wide-spread use, given that parsing + iterwalk would usually be replaced with the more efficient iterparse function. However, an XML converter that serialises to C14N would also be vulnerable, for example, and there are legitimate use cases for this code sequence. If untrusted input is received (also remotely) and processed via iterwalk function, a crash can be triggered.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 3 products from lxml, from xmlsoft, from fedoraproject organizations running these solutions should prioritize assessment and patching.
Reported in 2022, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2022-07-05T10:15:08.763
2025-11-04T16:15:49.557
Modified
CVSSv3.1: 7.5 (HIGH)
AV:N/AC:L/Au:N/C:N/I:N/A:P
10.0
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | lxml | lxml | < 4.9.1 | Yes |
| Application | xmlsoft | libxml2 | ≤ 2.9.14 | No |
| Operating System | fedoraproject | fedora | 36 | Yes |
| Operating System | fedoraproject | fedora | 37 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For lxml's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.