Incorrect Calculation of Buffer Size Affecting thunderbird package, versions <0:140.12.0-1.amzn2.0.1


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.11% (2nd percentile)

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  • Snyk IDSNYK-AMZN2-THUNDERBIRD-17883968
  • 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 thunderbird to version 0:140.12.0-1.amzn2.0.1 or higher.
This issue was patched in ALAS2-2026-3795.

NVD Description

Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird 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