CVE-2021-3537
libxml2: NULL pointer dereference when post-validating mixed content parsed in recovery mode
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 1, 2021
Updated · October 14, 2026
Description
A NULL pointer dereference flaw was found in libxml2, where it did not propagate errors while parsing XML mixed content. This flaw causes the application to crash if an untrusted XML document is parsed in recovery mode and post validated. The highest threat from this vulnerability is to system availability.
Statement
For the flaw to be exploitable, the document must be parsed in recovery mode and post validated (e.g.: when used in the xmlling tool, both -recover and -postvalid options must be used for the flaw to be exploitable)
CVSS score applicability
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
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference