CVE-2026-102497: Apache XMLSchema: Denial of service through cyclic schema definitions in the schema walker

[Colm O hEigeartaigh <coheigea () apache org>]

Severity: low 

Affected versions:

- Apache XMLSchema before 2.3.3

Description:

The Apache XmlSchema walker (xmlschema-walker) doesn't detect cycles in type derivation, substitution groups, model 
groups or attribute groups. A malicious schema with such a cycle can make the walker recurse until the stack overflows, 
causing a denial of service.

Users are recommended to upgrade to version 2.3.3, which fixes this issue.

Credit:

This issue was found using Claude agents to study the security of open-source projects (finder)

References:

https://ws.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-102497