CVE-2026-39998

Analyzed Analyzed - Analysis Complete

Improper Input Validation in Apache APISIX

Publication date: 2026-06-19

Last updated on: 2026-06-23

Assigner: Apache Software Foundation

Description

Improper Input Validation vulnerability in Apache APISIX. The attacker can take advantage of certain configuration in forward-auth plugin to spoof identity headers. This issue affects Apache APISIX: from 2.12.0 through 3.16.0. Users are recommended to upgrade to version 3.17.0, which fixes the issue.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-06-19

Last Modified

2026-06-23

Generated

2026-07-10

AI Q&A

2026-06-19

EPSS Evaluated

2026-07-08

NVD

CVE-2026-39998

EUVD

EUVD-2026-38011

Affected Vendors & Products

Vendor	Product	Version / Range
apache	apisix	From 2.12.0 (inc) to 3.17.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-20	The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Attack-Flow Graph

Executive Summary

This vulnerability is an improper input validation issue in the Apache APISIX forward-auth plugin. It allows an attacker to exploit certain configurations to spoof identity headers.

The flaw affects Apache APISIX versions from 2.12.0 through 3.16.0 and is fixed in version 3.16.1 (or 3.17.0 as per the description).

Impact Analysis

An attacker exploiting this vulnerability can spoof identity headers, potentially impersonating other users or services.

This can lead to unauthorized access or actions within systems relying on Apache APISIX for authentication or identity verification.

Mitigation Strategies

To mitigate the CVE-2026-39998 vulnerability, users should upgrade Apache APISIX to version 3.17.0 or later, where the issue is fixed.

This vulnerability arises from improper input validation in the forward-auth plugin, allowing attackers to spoof identity headers if certain configurations are used.

Therefore, upgrading to the fixed version is the recommended immediate step to prevent exploitation.

Compliance Impact

The vulnerability allows attackers to spoof identity headers by exploiting improper input validation in the forward-auth plugin of Apache APISIX. This could potentially lead to unauthorized access or identity spoofing.

Such unauthorized access or identity spoofing may impact compliance with standards and regulations like GDPR and HIPAA, which require strict controls on identity verification and access management to protect personal and sensitive data.

However, the provided information does not explicitly describe the direct effects on compliance with these standards.

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