CVE-2026-87830

Critical

Description

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.

SeverityCritical

CVSS9.1

Exploit probability—

Product

Apache Wss4j

PublishedSep 30, 2026

First seenSep 30, 2026

Weakness typeCWE-917Expression language injection

How to fix

Update

apache wss4j2.4.4, 3.0.6, 4.0.2 or later

Vendor advisories

lists.apache.org/thread.html/lwlozb1x20d16f9dnyvoygc9rrhzq2vn

Affected products

Product	Affected versions	Fixed in
apache wss4j	v < 2.4.4, 3.0.0 ≤ v < 3.0.6, 4.0.0 ≤ v < 4.0.2	2.4.4, 3.0.6, 4.0.2

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