Apache WSS4J flag bug allows XML Signature Wrapping fixed 4.0.2/3.0.6/2.4.4
CVE-2026-92121 Published on September 30, 2026
Apache WSS4J: WS-SecurityPolicy signature checks skipped in the streaming code after an STR-Transform reference
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.
Vulnerability Analysis
CVE-2026-92121 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.
Weakness Type
Protection Mechanism Failure
The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. This weakness covers three distinct situations. A "missing" protection mechanism occurs when the application does not define any mechanism against a certain class of attack. An "insufficient" protection mechanism might provide some defenses - for example, against the most common attacks - but it does not protect against everything that is intended. Finally, an "ignored" mechanism occurs when a mechanism is available and in active use within the product, but the developer has not applied it in some code path.
Products Associated with CVE-2026-92121
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Affected Versions
Apache Software Foundation Apache WSS4J:- Version 4.0.0 and below 4.0.2 is affected.
- Version 3.0.0 and below 3.0.6 is affected.
- Before 2.4.4 is affected.