CVE-2026-87830: Apache WSS4J

Critical severity, CVSS 9.1. EPSS: 0.2% chance of exploitation in the next 30 days.

In the StAX streaming WS-SecurityPolicy validator, certain relative or unsupported XPath expressions can be converted into paths that never match the actual XML element path. A remote SOAP peer may therefore send a required element without the expected signature or encryption. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4, which fix this issue.

Affected products

• Apache WSS4J: before 2.4.4 (fixed in 2.4.4); from 3.0.0, before 3.0.6 (fixed in 3.0.6); from 4.0.0, before 4.0.2 (fixed in 4.0.2)

Published 2026-09-30. Last modified 2026-10-06.