CVE-2026-56131: Use After Free

Published Jun 19, 2026
·
Updated

libexpat before 2.8.2 lacks handler call depth tracking for calls to XMLResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).

Affected Software

3 affected componentsFixes available
Expat libexpat<2.8.2
Libexpat Project Libexpat<2.8.2
Microsoft azl3 expat 2.6.4-6<2.8.2-1
2.8.2-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.8.2-1

Event History

Jun 19, 2026
CVE Published
via MITRE·02:56 AM
Data Sourced
via MITRE·02:56 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:17 AM
RemedyDescriptionSeverityWeaknessAffected Software
Jun 27, 2026
Data Sourced
via Microsoft·08:07 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:07 AM
DescriptionSeverity

Frequently Asked Questions

1

What is the severity of CVE-2026-56131?

The severity of CVE-2026-56131 is medium with a score of 4.9.

2

What type of vulnerability is CVE-2026-56131?

CVE-2026-56131 is classified as a Use After Free vulnerability.

3

How does CVE-2026-56131 affect the libexpat library?

CVE-2026-56131 affects libexpat by potentially allowing a use-after-free condition during handler calls, which can lead to data corruption.

4

How do I fix CVE-2026-56131?

To fix CVE-2026-56131, upgrade to libexpat version 2.8.2 or later, where the vulnerability is addressed.

5

What are the consequences of exploitation of CVE-2026-56131?

Exploitation of CVE-2026-56131 can lead to application crashes or arbitrary code execution due to the use-after-free condition.

Contact

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