Algorithmic Complexity Affecting expat package, versions <2.8.4-160000.1.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.74% (53rd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-SLES1600-EXPAT-20306249
  • published30 Sept 2026
  • disclosed24 Sept 2026

Introduced: 24 Sep 2026

NewCVE-2026-66046  (opens in a new tab)
CWE-407  (opens in a new tab)

How to fix?

Upgrade SLES:16.0.0 expat to version 2.8.4-160000.1.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream expat package and not the expat package as distributed by SLES. See How to fix? for SLES:16.0.0 relevant fixed versions and status.

Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.

CVSS Base Scores

version 3.1