VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVPublished CVSS 7.5 highEPSS 0.5% probability of exploitation in 30 daysFound by AI: Anthropic (Claude)
Apache

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

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?
0.5%

EPSS score, percentile 44.6 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
7.5 High

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

  • before 2.3.3

Versions by product

Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

What to do

Advisories and patches

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Apache Software Foundation Apache XMLSchema
StatusVersions
Affectedbefore 2.3.3

Versions not listed are: unaffected.

Source: CVE List, as of . About the data.

About this vulnerability

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.

Summary: CVE record, as of .

  • CISA has not added CVE-2026-102497 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
  • The CVE record was published on 29 Sep 2026.
  • The CVE record carries a CVSS v3.1 base score of 7.5 (High), taken from CISA's enrichment of the record.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 44.6), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
  • CISA's SSVC assessment in the CVE record: exploitation none, automatable yes, technical impact partial.
  • The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.

Description

Apache XMLSchema: Denial of service through cyclic schema definitions in the schema walker

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.

Source: CVE List, as of . About the data.

Weakness

CWE-674

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published

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