CVE-2026-92899
Received Received - Intake

UsernameToken Replay in Apache WSS4J

Publication date: 2026-09-30

Last updated on: 2026-09-30

Assigner: Apache Software Foundation

Description
Apache WSS4J remembers the Nonce of each UsernameToken it accepts, so a captured token cannot be reused. It stored the Nonce as raw base64 text, but authentication decodes that text and uses the bytes.The same bytes can be written as base64 in several ways. An attacker who captured an authenticated request could re-send it with a space added to the Nonce: the password digest still verified, but the token no longer matched the remembered one, so the replay was accepted. Since a UsernameToken does not cover the message body, the captured token could then be reused on requests of the attacker's choosing until it expired. Affects deployments with a nonce replay cache configured, as Apache CXF has by default, and only tokens using a password digest. The cache is now keyed on the decoded Nonce. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4, which fix this issue.

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Meta Information

Published
2026-09-30
Last Modified
2026-09-30
Generated
2026-09-30
AI Q&A
2026-09-30
EPSS Evaluated
N/A
NVD
CVE-2026-92899
EUVD
EUVD-2026-89798

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
apache wss4j From 4.0.2 (inc)
apache wss4j From 3.0.6 (inc)
apache wss4j From 2.4.4 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-290 This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Attack-Flow Graph

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Executive Summary

This vulnerability in Apache WSS4J allows bypassing username token replay protection by re-encoding the Nonce. The system stores the Nonce as raw base64 text but decodes it during authentication, enabling multiple base64 representations of the same bytes. An attacker can capture an authenticated request, modify the Nonce by adding a space, and resend it. The password digest still verifies, but the token no longer matches the stored Nonce, allowing replay attacks.

Detection Guidance

Detecting this vulnerability requires checking if your Apache WSS4J version is affected. Use commands like 'mvn dependency:tree' for Maven projects or check package managers like 'rpm -qa | grep wss4j' or 'dpkg -l | grep wss4j' to identify installed versions. Compare against versions 4.0.2, 3.0.6, or 2.4.4.

Impact Analysis

An attacker could reuse captured authenticated requests to perform unauthorized actions on your system. Since the UsernameToken does not cover the message body, the attacker can modify requests to their choosing until the token expires. This could lead to data breaches, unauthorized access, or other malicious activities depending on the system's functionality.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches, which may violate compliance requirements under GDPR, HIPAA, or other regulations. Organizations must ensure secure authentication mechanisms to maintain compliance, and this issue undermines those protections.

Mitigation Strategies

Upgrade Apache WSS4J to versions 4.0.2, 3.0.6, or 2.4.4 or later. If upgrading is not immediately possible, disable the nonce replay cache or ensure tokens do not use password digests until patched.

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