What is CVE-2026-88920?

CVE-2026-88920 is a critical-severity vulnerability, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-09-30.

How severe is CVE-2026-88920?

Critical severity. CVSS v3 base score is 9.8 out of 10.

CVE-2026-88920

CVE-2026-88920

An authentication bypass in the DOM security processor in Apache WSS4J allows unauthenticated remote attackers to forge authenticated SOAP messages via a crafted unsigned SAML sender-vouches assertion containing an attacker-controlled key. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4, which fix this issue.

Vulnerability class: Broken Authentication

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

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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-287 — Improper Authentication

References

lists.apache.org/thread.html/grt43m3bgbzz0mk0cnho3rcybb1j01z9 (vendor-advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-88920?: CVE-2026-88920 is a critical-severity vulnerability, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-09-30.
How severe is CVE-2026-88920?: Critical severity. CVSS v3 base score is 9.8 out of 10.