CVE-2026-4224 MEDIUM

CVE-2026-4224: Stack overflow parsing XML with deeply nested DTD content models

Vendor Python Software Foundation
Product CPython
Published March 16, 2026
Last update April 8, 2026
View on NVD All CVEs

CVSS base score

6.0/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs.

Key dates

02Disclosure timeline

March 16, 2026 CVE published
April 8, 2026 Record updated