CVE-2026-87830

EUVD-2026-89792
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.
Expression Language Injection
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
apacheCNA
9.1 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
apachewss4j
4.0.0 ≤
𝑥
< 4.0.2
CNA
apachewss4j
3.0.0 ≤
𝑥
< 3.0.6
CNA
apachewss4j
𝑥
< 2.4.4
CNA
Debian logo
Debian Releases
Debian Product
Codename
wss4j
bookworm
vulnerable
forky
vulnerable
sid
vulnerable
trixie
vulnerable
Common Weakness Enumeration
References
https://lists.apache.org/thread.html/lwlozb1x20d16f9dnyvoygc9rrhzq2vn
http://www.openwall.com/lists/oss-security/2026/09/30/9