High severity · published May 10, 2026
CVE-2026-45186
In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
libexpat · libexpat project
before 2.8.1 · source: vendor, NVD
RH
Red Hat Discovery 2 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Update Infrastructure 5 · Red Hat
All versions, or not specified · source: CISA
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.5 before V3.1.6; V3.1.5 before V3.1.6 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.5 before V3.1.6; V3.1.5 before V3.1.6 · source: CISA
SS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.5 before V3.1.6 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45186
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-45186
Exploit
https://github.com/libexpat/libexpat/pull/1216
Mailing List
http://www.openwall.com/lists/oss-security/2026/05/11/16
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22715
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22721
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:23230
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26319
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