CVE-2026-108039: apache software foundation apache cxf XML Entity Expansion

Vulnerability summary

CVE-2026-108039 is a high (CVSS 7.5) XML Entity Expansion vulnerability in apache software foundation apache cxf. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.2% of scored vulnerabilities.

Timeline

1. 09-10-2026
   PublishedVulnerability first disclosed.
2. 15-10-2026
   Last modifiedVulnerability information updated.

Description

By default, StaxUtils placed no limit on the total number of elements or the total number of characters in an XML document. A very large request could therefore use a lot of memory and CPU during parsing, especially where CXF builds a DOM from the input (for example SAAJ or WS-Security), and could cause a denial of service when no request size limit was configured. Both limits now have defaults: the maximum element count is 100 × maxChildElements (5,000,000 by default), and the maximum document size is 256M characters. Applications that process larger documents can raise the limits with the org.apache.cxf.stax.maxElementCount and org.apache.cxf.stax.maxXMLCharacters properties. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

• CWE-776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.