CVE-2026-4942: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-cffx-9q2g-r6hp
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CVSS 5.9
CWE-757
Published
Advisory Summary

CVE-2026-4942 is a MODERATE (CVSS 5.9) security vulnerability vulnerability (CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')) affecting Software libraries in the Maven ecosystem. The weakness occurs when a protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-4942 at a Glance

CVE Identifier CVE-2026-4942
GHSA Identifier GHSA-cffx-9q2g-r6hp
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.9

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

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

How to Fix CVE-2026-4942

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-2026-4942, 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-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade'), where a protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties. 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

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to send a specifically crafted message and downgrade the Transport Layer Security (TLS) protocol to a version disabled in the server configuration.

References

NVD — CVE-2026-4942 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4942
www.ibm.com/support/pages/node/... WEB
https://www.ibm.com/support/pages/node/7278992

Frequently Asked Questions

What is CVE-2026-4942?
CVE-2026-4942 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-4942?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-4942?
CVE-2026-4942 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-4942?
CVE-2026-4942 is classified under CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade') (A protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties.).
How can I check Maven dependencies for CVE-2026-4942?
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-cffx-9q2g-r6hp",
  "modified" : "2026-07-17T21:31:44Z",
  "published" : "2026-07-17T21:31:44Z",
  "aliases" : [ "CVE-2026-4942" ],
  "details" : "IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to send a specifically crafted message and downgrade the Transport Layer Security (TLS) protocol to a version disabled in the server configuration.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4942"
  }, {
    "type" : "WEB",
    "url" : "https://www.ibm.com/support/pages/node/7278992"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-757" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-17T20:17:23Z"
  }
}