Denial of Service via Attribute Name Collision in libexpat < 2.8.1
CVE-2026-45186 Published on May 10, 2026

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.

NVD

Vulnerability Analysis

CVE-2026-45186 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

Inefficient Algorithmic Complexity

An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.


Products Associated with CVE-2026-45186

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-45186 are published in these products:

Libexpatproject Libexpat
 
Red Hat Http Server
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Discovery
 
Red Hat Jboss Core Services
 
Red Hat Rhui
 

Affected Versions

libexpat project libexpat: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat JBoss Core Services 2.4.62.SP4: Red Hat Discovery 2: Red Hat Discovery 2: Red Hat Update Infrastructure 5: Red Hat Update Infrastructure 5: Red Hat Update Infrastructure 5: Red Hat Update Infrastructure 5: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP:

Exploit Probability

EPSS
0.44%
Percentile
36.26%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.