CVE-2021-42521
CVSS v3
7.5
HIGH
EPSS Score
1.3 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
There is a NULL pointer dereference vulnerability in VTK before 9.2.5, and it lies in IO/Infovis/vtkXMLTreeReader.cxx. The vendor didn't check the return value of libxml2 API 'xmlDocGetRootElement', and try to dereference it. It is unsafe as the return value can be NULL and that NULL pointer dereference may crash the application.
Technical details
- Published
- 2022-08-25
Frequently asked questions
What is CVE-2021-42521?
There is a NULL pointer dereference vulnerability in VTK before 9.2.5, and it lies in IO/Infovis/vtkXMLTreeReader.cxx. The vendor didn't check the return value of libxml2 API 'xmlDocGetRootElement', and try to dereference it. It is unsafe as the return value can be NULL and that NULL pointer dereference may crash the application.
Is CVE-2021-42521 actively exploited?
Active exploitation of CVE-2021-42521 has not been confirmed. Its EPSS score was 1.3% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-42521?
CVE-2021-42521 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2021-42521 affecting your environment?
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