High 8.6Published May 19, 2021

CVE-2021-3517There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11.

Updated under an hour ago (Oct 26, 2026, 11:25 PM ET)

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It affects Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP and 30 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP

Exploited in the last 30 days

There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.

CVSS: 8.6 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
Weakness (CWE): CWE-787, CWE-125
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: redhat
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
xmlsoft libxml2 xmlsoft:libxml2	before 2.9.11	NVD
redhat jboss_core_services redhat:jboss_core_services	all versions	NVD
redhat enterprise_linux redhat:enterprise_linux	8.0	NVD
fedoraproject fedora fedoraproject:fedora	33; 34	NVD
debian debian_linux debian:debian_linux	9.0	NVD
netapp active_iq_unified_manager netapp:active_iq_unified_manager	all versions; all versions	NVD
netapp clustered_data_ontap netapp:clustered_data_ontap	all versions	NVD
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References

References

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4GY3NIV52WV/	vendor-advisory, x-refsource-fedora
https://lists.debian.org/debian-lts-announce/2021/05/msg00008.html	mailing-list, x-refsource-mlist, third-party-advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1954232	x-refsource-misc, issue-tracking, patch, third-party-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6YIZAFDGX6/	vendor-advisory, x-refsource-fedora
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E	mailing-list, x-refsource-mlist
https://security.gentoo.org/glsa/202107-05	vendor-advisory, x-refsource-gentoo, third-party-advisory
https://security.netapp.com/advisory/ntap-20210625-0002/	x-refsource-confirm, third-party-advisory
https://www.oracle.com/security-alerts/cpuoct2021.html	x-refsource-misc, patch, third-party-advisory
https://www.oracle.com/security-alerts/cpujan2022.html	x-refsource-misc, patch, third-party-advisory
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.