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Vulnerability record · CVE-2021-3518 · published 18 May 2021

CVE-2021-3518: Xmlsoft libxml2 use after free vulnerability

Xmlsoft · Libxml2

There's a flaw in libxml2 in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by an application linked with libxml2 could trigger a use-after-free. The greatest impact from this flaw is to confidentiality, integrity, and availability.

8.8 CVSS 3.1 High EPSS 22% · top 2.4% CWE-416 · Use after free
8.8CVSS 3.1 base score, v2 6.8
22%EPSS exploitation probability, 30 days
NoNot in CISA KEV
18Affected product versions listed by NVD
38References
17 Jun 2026Last modified by NVD

Description

There's a flaw in libxml2 in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by an application linked with libxml2 could trigger a use-after-free. The greatest impact from this flaw is to confidentiality, integrity, and availability.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

18 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://seclists.org/fulldisclosure/2021/Jul/54 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/55 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/58 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/59 Mailing ListThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1954242 Issue TrackingPatchThird Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.ap
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.ap
https://lists.debian.org/debian-lts-announce/2021/05/msg00008.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4G
https://security.gentoo.org/glsa/202107-05 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210625-0002/ Third Party Advisory
https://support.apple.com/kb/HT212601 Third Party Advisory
https://support.apple.com/kb/HT212602 Third Party Advisory
https://support.apple.com/kb/HT212604 Third Party Advisory
https://support.apple.com/kb/HT212605 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html PatchThird Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Not Applicable
https://www.oracle.com/security-alerts/cpuoct2021.html PatchThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/54 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/55 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/58 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Jul/59 Mailing ListThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1954242 Issue TrackingPatchThird Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.ap
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.ap
https://lists.debian.org/debian-lts-announce/2021/05/msg00008.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4G
https://security.gentoo.org/glsa/202107-05 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210625-0002/ Third Party Advisory
https://support.apple.com/kb/HT212601 Third Party Advisory
https://support.apple.com/kb/HT212602 Third Party Advisory
https://support.apple.com/kb/HT212604 Third Party Advisory
https://support.apple.com/kb/HT212605 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html PatchThird Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Not Applicable
https://www.oracle.com/security-alerts/cpuoct2021.html PatchThird Party Advisory

Track CVE-2021-3518 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

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Source: NIST National Vulnerability Database (record CVE-2021-3518), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.