CVE-2026-45186

Siemens ProductCERT Advisory SSA-082556

Description

A flaw was found in libexpat. When processing a specially crafted XML input containing a specific pattern of attributes, the parsing time increases quadratically due to checks for attribute name collisions. This consumes excessive CPU resources and eventually results in a denial of service.

Metrics

Severity
high
no public PoC known
7.5
Source: nvd-v3
38.6 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
0.5 %
Low — model estimates < 1% exploitation likelihood.
Published
2021-09-26 00:00 UTC
CWE-407

Weakness classes (CWE)

  • CWE-407Class

    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.

    cwe.mitre.org →

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-08-25 13:19 UTC· 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
    • Reference: https://access.redhat.com/errata/RHSA-2026:58981
  2. CVE Translated2026-07-24 20:10 UTC· nvd@nist.gov
    • Translation: Title: libexpat de libexpat project, Description: En libexpat antes de 2.8.1, la complejidad computacional de las comprobaciones de colisión de nombres de atributos permite una denegación de servicio a través de una entrada XML manipulada de tamaño moderado.

Affected operating systems

  • bsd

    freebsd / freebsd13.2

  • bsd

    freebsd / freebsd13.3

  • bsd

    freebsd / freebsd14.0

  • bsd

    freebsd / freebsd14.1

  • bsd

    netbsd / netbsd

  • linux

    almalinux / almalinux9.0

  • linux

    amazon / amazon_linux2023.0

  • linux

    amazon / amazon_linux

  • linux

    ubuntu / awsbionic

  • linux

    ubuntu / awsjammy

  • linux

    ubuntu / awsnoble

  • linux

    ubuntu / awsresolute

  • linux

    ubuntu / awsxenial

  • linux

    ubuntu / aws-6.8jammy

  • linux

    ubuntu / aws-hwexenial

  • linux

    ubuntu / azurejammy

  • linux

    ubuntu / azurenoble

  • linux

    ubuntu / azureresolute

  • linux

    ubuntu / azurexenial

  • linux

    ubuntu / azure-4.15bionic

  • linux

    suse / basesystem_module15

  • linux

    debian / debian_linux10.0

  • linux

    debian / debian_linux11.0

  • linux

    debian / debian_linux12.0

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • android

    :linux_kernel::0

  • android

    :linux_kernel:Kernel

  • arista

    cloudvision_agni2024.4.0 – 2025.2.2

  • arista

    cloudvision_portal2024.2.0 – 2026.1.0

  • arista

    velocloud_edge4.5.0 – 6.4.1

  • arista

    velocloud_gateway

  • arista

    velocloud_orchestrator

  • bitnami

    java-min1.9.0

  • bitnami

    varnish6.1.0

  • bitnami

    varnish7.4.0

  • Dell

    ECS3.8.1.0-3.8.1.7

  • Dell

    NetWorkervProxy 19.14

  • Dell

    PowerScale OneFSNode Firmware Package 14.1

  • Dell

    Secure Connect GatewayAppliance 5.32.00.18

  • Dell

    Secure Connect Gateway< 5.36.00.16

    fixed in 5.36.00.16

  • Dell

    Secure Connect GatewayAppliance <5.32.00.18

  • gnu

    glibc2.35 – 2.37

  • gnu

    glibc

  • gnupg

    libgcrypt1.11.0 – 1.11.3

  • gnupg

    libgcrypt1.12.0 – 1.12.2

  • gnupg

    libgcrypt1.8.8 – 1.10.4

  • hackage

    xz-clib5.6.3

  • hackage

    xz-clib5.6.4

  • hackage

    xz-clib5.8.0

References & sources

Linked CVEs

Show 291 more CVEs
IDCVE-2026-45186