CVE-2026-93483: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-g4fx-r8m5-c6r7
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CWE-348
Published
Advisory Summary

CVE-2026-93483 is a CRITICAL security vulnerability vulnerability (CWE-348: Use of Less Trusted Source) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-93483 at a Glance

CVE Identifier CVE-2026-93483
GHSA Identifier GHSA-g4fx-r8m5-c6r7
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification CWE-348: Use of Less Trusted Source
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-93483

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-2026-93483, 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-348: Use of Less Trusted Source, where the product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack. 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

In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this header, an attacker can impersonate any user, including administrators, without requiring a password. This grants full access to confidential data and system controls. More specifically, the HTTPBasicAuth modules for the agent (Kernel::System::Auth::HTTPBasicAuth) and customer (Kernel::System::CustomerAuth::HTTPBasicAuth) interfaces read the username to log in not only from $ENV{REMOTE_USER} (set by the web server after successful authentication), but also, as a fallback, from $ENV{HTTP_REMOTE_USER}, which is populated directly from an attacker-controllable "Remote-User" request header. On systems where HTTPBasicAuth was configured as the authentication backend, this allowed an attacker to log in as any existing user by sending a request with a forged Remote-User header, without providing any credentials.

References

NVD — CVE-2026-93483 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-93483
www.znuny.org/advisories WEB
https://www.znuny.org/advisories
www.znuny.org/en/advisories/zsa-2... WEB
https://www.znuny.org/en/advisories/zsa-2026-14

Frequently Asked Questions

What is CVE-2026-93483?
CVE-2026-93483 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-348: Use of Less Trusted Source.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-93483?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-93483?
CVE-2026-93483 is classified under CWE-348: Use of Less Trusted Source (The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.).
How can I check Maven dependencies for CVE-2026-93483?
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-g4fx-r8m5-c6r7",
  "modified" : "2026-10-15T06:30:43Z",
  "published" : "2026-10-15T06:30:43Z",
  "aliases" : [ "CVE-2026-93483" ],
  "details" : "In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this header, an attacker can impersonate any user, including administrators, without requiring a password. This grants full access to confidential data and system controls. More specifically, the HTTPBasicAuth modules for the agent (Kernel::System::Auth::HTTPBasicAuth) and customer (Kernel::System::CustomerAuth::HTTPBasicAuth) interfaces read the username to log in not only from $ENV{REMOTE_USER} (set by the web server after successful authentication), but also, as a fallback, from $ENV{HTTP_REMOTE_USER}, which is populated directly from an attacker-controllable \"Remote-User\" request header. On systems where HTTPBasicAuth was configured as the authentication backend, this allowed an attacker to log in as any existing user by sending a request with a forged Remote-User header, without providing any credentials.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/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:Y/R:U/V:X/RE:L/U:Red"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-93483"
  }, {
    "type" : "WEB",
    "url" : "https://www.znuny.org/advisories"
  }, {
    "type" : "WEB",
    "url" : "https://www.znuny.org/en/advisories/zsa-2026-14"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-348" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-10-15T04:18:30Z"
  }
}