---
id: CVE-2026-87830
title: >-
  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
summary: >-
  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 witho…
severity: none
vendor: Apache Software Foundation
product: 'org.apache.wss4j:wss4j-ws-security-policy-stax'
affected:
  - 'org.apache.wss4j:wss4j-ws-security-policy-stax >= 4.0.0 < 4.0.2'
  - 'org.apache.wss4j:wss4j-ws-security-policy-stax >= 3.0.0 < 3.0.6'
  - 'org.apache.wss4j:wss4j-ws-security-policy-stax < 2.4.4'
published: '2026-09-30'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T13:17:21.350'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-87830'
references:
  - url: 'https://lists.apache.org/thread.html/lwlozb1x20d16f9dnyvoygc9rrhzq2vn'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/30/9'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-30T12:02:58.585Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.