CVE-2026-71187: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-rj7p-436q-6xv2
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CVSS 9.8
CWE-603
Published
Advisory Summary

CVE-2026-71187 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (CWE-603: Use of Client-Side Authentication) affecting Software libraries in the Maven ecosystem. The weakness occurs when a client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-71187 at a Glance

CVE Identifier CVE-2026-71187
GHSA Identifier GHSA-rj7p-436q-6xv2
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-603: Use of Client-Side Authentication
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-71187

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-71187, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-603: Use of Client-Side Authentication, where a client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The Ebyte device relies on client side authentication logic that can be reproduced by unauthenticated users. An attacker may generate valid authentication requests and bypass authentication to obtain administrative access to the device.

References

NVD — CVE-2026-71187 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-71187
Software Source Repository REPOSITORY
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-237-06.json
www.cisa.gov/news-events/ics-adv... WEB
https://www.cisa.gov/news-events/ics-advisories/icsa-26-237-06

Frequently Asked Questions

What is CVE-2026-71187?
CVE-2026-71187 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-603: Use of Client-Side Authentication.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-71187?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-71187?
CVE-2026-71187 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-71187?
CVE-2026-71187 is classified under CWE-603: Use of Client-Side Authentication (A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.).
How can I check Maven dependencies for CVE-2026-71187?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rj7p-436q-6xv2",
  "modified" : "2026-08-28T00:32:03Z",
  "published" : "2026-08-28T00:32:03Z",
  "aliases" : [ "CVE-2026-71187" ],
  "details" : "The Ebyte device relies on client side authentication logic that can be \nreproduced by unauthenticated users. An attacker may generate valid \nauthentication requests and bypass authentication to obtain \nadministrative access to the device.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-71187"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-237-06.json"
  }, {
    "type" : "WEB",
    "url" : "https://www.cisa.gov/news-events/ics-advisories/icsa-26-237-06"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-603" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-28T00:18:09Z"
  }
}