CVE-2026-102497
Apache XMLSchema: Denial of service through cyclic schema definitions in the schema walker
Apache Software Foundation Apache XMLSchema
CVSS
7.5HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.53%Chance of exploitation activity in the next 30 days, higher than 43% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 2.3.3Apache XMLSchemaCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
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.
Text from CVE List
Affected versions 1
- Apache XMLSchemaaffected: all versions before 2.3.3CVE List