CVE-2026-102633: libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc

Published Sep 29, 2026
·
Updated

libexpat versions 2.7.2 through 2.8.5 contain an integer overflow vulnerability in expatrealloc() function on 32-bit platforms when computing allocation sizes. Attackers supplying malicious XML to applications parsing with vulnerable libexpat can cause heap buffer overflow, memory corruption, or denial of service.

Affected Software

1 affected component
Expat libexpat>=2.7.2<=2.8.5

Event History

Sep 29, 2026
CVE Published
via MITRE·04:04 PM
Data Sourced
via MITRE·04:04 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

Which systems are affected?

The issue affects applications that parse attacker-supplied XML using libexpat versions 2.7.2 through 2.8.5 on 32-bit platforms. The provided information does not indicate an impact on 64-bit platforms.

2

What does an attacker need to exploit this issue?

An attacker needs to supply malicious XML to an application that parses it with a vulnerable libexpat version. No authentication or user interaction is required, but the attack complexity is rated high.

3

What is the potential impact?

Successful exploitation can cause a heap buffer overflow and memory corruption, or result in denial of service. The supplied severity vector indicates availability impact, with no stated confidentiality or integrity impact.

Contact

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