Home/CVE/A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while parsing XML mixe
CVE

CVE-2021-3537

A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while parsing XML mixe

A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while parsing XML mixed content, causing a NULL dereference. If an untrusted XML document was parsed in recovery mode and post-validated, the flaw could be used to crash the application. The highest threat from this vulnerability is to system availability.

MEDIUM · CVSS 5.9 EPSS 0.00111
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-476NULL Pointer Dereference
CWE-476NULL Pointer Dereference
▤

Affected Products & Versions

19
xmlsoft libxml2< 2.9.11
redhat jboss core servicesall versions
redhat enterprise linuxall versions
debian linuxall versions
fedoraproject fedoraall versions
netapp active iq unified managerall versions
netapp clustered data ontapall versions
netapp clustered data ontap antivirus connectorall versions
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
RubyGems nokogiri MODERATE fixed in 1.11.4
▣

Scoring & Timeline

5.9
MEDIUM · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD14 May 2021 · 08:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
⚑

Vendor Advisories

21
suse-csafopenSUSE-SU-2026:10356-1
suse-csafopenSUSE-SU-2025:14697-1
suse-csafopenSUSE-SU-2024:14174-1
suse-csafopenSUSE-SU-2024:11016-1
suse-csafopenSUSE-SU-2024:11340-1
🔗

References & Sources

9
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://bugzilla.redhat.com/show_bug.cgi?id=1956522Issue TrackingPatchThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/05/msg00008.htmlMailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6YIZAFDGX6/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4GY3NIV52WV/
https://security.gentoo.org/glsa/202107-05Third Party Advisory
https://security.netapp.com/advisory/ntap-20210625-0002/Third Party Advisory
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