Incorrect Calculation of Buffer Size Affecting expat-static package, versions <0:2.1.0-15.amzn2.0.7


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.1% (1st percentile)

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  • Snyk IDSNYK-AMZN2-EXPATSTATIC-17883915
  • published8 Jul 2026
  • disclosed19 Jun 2026

Introduced: 19 Jun 2026

CVE-2026-56132  (opens in a new tab)
CWE-131  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2 expat-static to version 0:2.1.0-15.amzn2.0.7 or higher.
This issue was patched in ALAS2-2026-3495.

NVD Description

Note: Versions mentioned in the description apply only to the upstream expat-static package and not the expat-static package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is mishandled when there is data-structure sharing across parsers.

CVSS Base Scores

version 3.1