CVE-2026-87830: apache software foundation apache wss4j Expression Language Injection

Vulnerability summary

CVE-2026-87830 is a critical (CVSS 9.1) Expression Language Injection vulnerability in apache software foundation apache wss4j. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 10.8% of scored vulnerabilities.

Timeline

1. 30-09-2026
   PublishedVulnerability first disclosed.
2. 30-09-2026
   Last modifiedVulnerability information updated.

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.

• CWE-917Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')The product constructs all or part of an expression language (EL) statement in a framework such as a Java Server Page (JSP) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended EL statement before it is executed.