CVE-2026-102497 Apache XMLSchema: Denial of service through cyclic schema definitions in the schema walker
A malicious XML schema can cause infinite recursion in the Apache XMLSchema walker, leading to a stack overflow and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-102497?
CVE-2026-102497 is a high-severity denial of service vulnerability in Apache XMLSchema, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-674
Which versions are affected by CVE-2026-102497?
It affects 1 product.
Products include Apache Xmlschema.
How do I fix CVE-2026-102497?
No fix has been published for CVE-2026-102497 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-102497 being exploited?
There is no known exploitation of CVE-2026-102497 in the wild and no public exploit code.
Other vulnerabilities in Apache XMLSchema
Sources
Also known as GHSA-9wgm-rwmh-4mcv.