CVE-2026-97791

Undergoing Analysis Undergoing Analysis - In Progress

BaseFortify

Publication date: 2026-10-09

Last updated on: 2026-10-15

Assigner: Apache Software Foundation

Description

In Apache CXF, STSTokenValidator checks whether a SAML assertion is signed by a trusted certificate before deciding to send it to the STS. That result was stored in one object shared by all requests, so one request could read another's result. A remote, unauthenticated attacker could send a forged assertion signed with an untrusted certificate while legitimate requests were being processed, and it could be accepted as trusted without ever reaching the STS. Only services that use STSTokenValidator to validate SAML tokens without alwaysValidateToSts set are affected. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-10-09

Last Modified

2026-10-15

Generated

2026-10-19

AI Q&A

2026-10-09

EPSS Evaluated

2026-10-18

NVD

CVE-2026-97791

EUVD

EUVD-2026-95700

Affected Vendors & Products

Vendor	Product	Version / Range
Apache	Software	Foundation Apache CXF 4.2.0
Apache	Software	Foundation Apache CXF 4.0.0
Apache	Software	Foundation Apache CXF 0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Attack-Flow Graph

Executive Summary

This vulnerability in Apache CXF involves a shared object in STSTokenValidator that stores validation results for SAML assertions. A remote attacker can send a forged assertion signed with an untrusted certificate during legitimate requests. The forged assertion may be accepted as trusted without proper validation by the Security Token Service (STS). Only services using STSTokenValidator without alwaysValidateToSts set are affected.

Detection Guidance

To detect this vulnerability, check if your Apache CXF version is affected by running: 'cxf --version' or inspecting the JAR files for versions below 4.2.4, 4.1.9, or 3.6.13. Monitor logs for unexpected SAML token validations or unauthorized access attempts.

Impact Analysis

An attacker could exploit this to bypass authentication by having their forged SAML assertion accepted as valid. This could allow unauthorized access to protected resources or data. The impact depends on the service configuration but may lead to data breaches or privilege escalation.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating confidentiality requirements in GDPR and HIPAA. Organizations using affected Apache CXF versions may face compliance violations, potential fines, and reputational damage if exploited.

Mitigation Strategies

Upgrade Apache CXF to versions 4.2.4, 4.1.9, or 3.6.13 to fix the issue. Ensure services using STSTokenValidator do not have alwaysValidateToSts set to false.

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