Critical severity · published Sep 30, 2026
CVE-2026-88920
Apache WSS4J: SAML Sender-Vouches Authentication Bypass
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AW
Apache WSS4J · Apache Software Foundation
4.0.0 before 4.0.2; 3.0.0 before 3.0.6; before 2.4.4 · source: vendor
WS
Wss4j · Apache
before 2.4.4; 3.0.0 before 3.0.6; 4.0.0 before 4.0.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-88920
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-88920
vendor-advisory
https://lists.apache.org/thread.html/grt43m3bgbzz0mk0cnho3rcybb1j01z9
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