CVE-2026-56407: Integer Overflow
Last updated 24 September 2026
Other sources
libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.
— 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-2026-56407?
The severity of CVE-2026-56407 is rated as medium with a score of 6.9.
How do I fix CVE-2026-56407?
To fix CVE-2026-56407, you should upgrade to libexpat version 2.8.2 or later.
What vulnerabilities are associated with CVE-2026-56407?
CVE-2026-56407 is associated with an integer overflow vulnerability in the doProlog function of libexpat.
What impact does CVE-2026-56407 have on data security?
CVE-2026-56407 can lead to potential data corruption or unauthorized access due to the integer overflow.
Which software is affected by CVE-2026-56407?
CVE-2026-56407 affects versions of the Expat library before 2.8.2.