CVE-2026-56407mediumCWE-190

CVE-2026-56407: medium-severity vulnerability in libexpat

Published · Updated

Follow this CVE+ Monitor libexpat+ Monitor expat

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.9epss 0.2%
libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
Affected products
libexpat project · libexpat
Related CVEs — libexpat

In the same product, most dangerous first.

CVE-2025-59375HIGHCVE-2025-59375EPSS 1.4%CVE-2026-66046HIGHExpat Denial of Service via storeAtts() Quadratic ComplexityEPSS 0.7%CVE-2026-45186LOWCVE-2026-45186EPSS 0.5%CVE-2026-41080LOWCVE-2026-41080EPSS 0.4%CVE-2026-76956MEDIUMCVE-2026-76956EPSS 0.3%CVE-2026-32777MEDIUMCVE-2026-32777EPSS 0.2%