CVE-2026-56404: Integer Overflow
Last updated 21 September 2026
Other sources
libexpat before 2.8.2 has an integer overflow in addBinding.
— MITRE
Affected Software
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 - Upgrade
Upgrade
debian/expatto a version that resolves this vulnerability.Fixed in 2.5.0-1+deb12u3Fixed in 2.8.3-1~deb13u1Fixed in 2.8.4-1Fixed in 2.8.4-2 - Upgrade
Upgrade
libexpatto a version that resolves this vulnerability.Fixed in 2.8.2
Event History
Frequently Asked Questions
What is the severity of CVE-2026-56404?
The severity of CVE-2026-56404 is rated as medium with a score of 6.9.
What vulnerability does CVE-2026-56404 address?
CVE-2026-56404 addresses an integer overflow vulnerability in the Expat libexpat before version 2.8.2.
How do I fix CVE-2026-56404?
To fix CVE-2026-56404, you should upgrade Expat to version 2.8.2 or later.
What is the impact of CVE-2026-56404?
The impact of CVE-2026-56404 includes potential denial-of-service and data corruption vulnerabilities.
Which versions of Expat are affected by CVE-2026-56404?
CVE-2026-56404 affects all versions of Expat prior to 2.8.2.