What is CVE-2026-87830?

CVE-2026-87830 is a critical-severity vulnerability, classified under Improper Neutralization of Special Elements used in an Expression Language Statement (Expression Language Injection). CVSS score: 9.1/10. Published 2026-09-30.

How severe is CVE-2026-87830?

Critical severity. CVSS v3 base score is 9.1 out of 10.

CVE-2026-87830

CVE-2026-87830

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.

Vulnerability class: Log4Shell (CVE-2021-44228)

Published 2026-09-30 · last modified 2026-09-30.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Weakness classification (CWE)

CWE-917 — Improper Neutralization of Special Elements used in an Expression Language Statement (Expression Language Injection)

References

lists.apache.org/thread.html/lwlozb1x20d16f9dnyvoygc9rrhzq2vn (vendor-advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-87830?: CVE-2026-87830 is a critical-severity vulnerability, classified under Improper Neutralization of Special Elements used in an Expression Language Statement (Expression Language Injection). CVSS score: 9.1/10. Published 2026-09-30.
How severe is CVE-2026-87830?: Critical severity. CVSS v3 base score is 9.1 out of 10.