CVE-2026-56404: Integer Overflow
Published Jun 21, 2026
·Updated
libexpat before 2.8.2 has an integer overflow in addBinding.
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.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 2.8.2-1
Event History
Jun 21, 2026
CVE Published
via MITRE·03:45 PM
Data Sourced
via MITRE·03:45 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:16 PM
RemedyDescriptionSeverityWeaknessAffected Software
Jun 27, 2026
Data Sourced
via Microsoft·08:05 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:05 AM
DescriptionSeverity
Frequently Asked Questions
1
What is the severity of CVE-2026-56404?
The severity of CVE-2026-56404 is rated as medium with a score of 6.9.
2
What vulnerability does CVE-2026-56404 address?
CVE-2026-56404 addresses an integer overflow vulnerability in the Expat libexpat before version 2.8.2.
3
How do I fix CVE-2026-56404?
To fix CVE-2026-56404, you should upgrade Expat to version 2.8.2 or later.
4
What is the impact of CVE-2026-56404?
The impact of CVE-2026-56404 includes potential denial-of-service and data corruption vulnerabilities.
5
Which versions of Expat are affected by CVE-2026-56404?
CVE-2026-56404 affects all versions of Expat prior to 2.8.2.