CVE-2026-56406

Name: CVE-2026-56406
Creator: NVD / NIST
Published: 2026-06-21T16:16:27.87+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.9/10EPSS 0.10%

Last modified Jun 23, 2026

CVE-2026-56406 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse.. EPSS estimates a 0.10% chance of exploitation in the next 30 days.

Description

libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse.

Metrics

CVSS 3.1

6.9/10

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L

EPSS Probability

0.10%

1.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-190

Affected Software

Vendor	Product	Versions
Libexpat Project	Libexpat	< 2.8.2

References

https://github.com/libexpat/libexpat/pull/1255Patch, Issue Tracking

Timeline

Published: Jun 21, 2026
Last Modified: Jun 23, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-56406?

libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse.

How severe is CVE-2026-56406?

CVE-2026-56406 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.10% probability of exploitation in the next 30 days.

How do I fix CVE-2026-56406?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-56406?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST