CVE-2026-92121: Apache WSS4J: WS-SecurityPolicy signature checks skipped in the streaming code after an STR-Transform reference

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-30 · updated 2026-10-06
Weakness: CWE-693

Description

In the WSS4J streaming (StAX) code, a signature reference using the WS-Security STR-Transform leaves an internal "inside signed content" flag permanently set. The WS-SecurityPolicy enforcer uses that flag to decide whether an element needs checking, so it stops evaluating SignedParts and SignedElements for the rest of the message. A policy requiring the SOAP Body to be signed is then satisfied even when the Body carries no signature, removing the protection against XML Signature Wrapping. Signature verification itself is unaffected. The DOM code is not affected. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4 which fix this issue.

Affected products

Apache Software Foundation Apache WSS4J: before 2.4.4; from 3.0.0 before 3.0.6; from 4.0.0 before 4.0.2 — fixed in 2.4.4, 3.0.6, 4.0.2

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache WSS4J 2.4.4, 3.0.6, 4.0.2. Check the vendor advisory for mitigations.

References

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