CVE-2026-19931: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-rhw6-3rrg-mwjq
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CVSS 9.8
CWE-488
Published
Advisory Summary

CVE-2026-19931 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (CWE-488: Exposure of Data Element to Wrong Session) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-19931 at a Glance

CVE Identifier CVE-2026-19931
GHSA Identifier GHSA-rhw6-3rrg-mwjq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-488: Exposure of Data Element to Wrong Session
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-2026-19931

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-2026-19931, 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-488: Exposure of Data Element to Wrong Session, where the product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session. 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

A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previously authenticated connection.

References

NVD — CVE-2026-19931 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-19931
hackerone.com/reports/3923520 WEB
https://hackerone.com/reports/3923520
curl.se/docs/cve-2026-19931... WEB
https://curl.se/docs/CVE-2026-19931.html
curl.se/docs/cve-2026-19931... WEB
https://curl.se/docs/CVE-2026-19931.json

Frequently Asked Questions

What is CVE-2026-19931?
CVE-2026-19931 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-488: Exposure of Data Element to Wrong Session.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-19931?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-19931?
CVE-2026-19931 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-2026-19931?
CVE-2026-19931 is classified under CWE-488: Exposure of Data Element to Wrong Session (The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.).
How can I check Maven dependencies for CVE-2026-19931?
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-rhw6-3rrg-mwjq",
  "modified" : "2026-09-08T18:31:45Z",
  "published" : "2026-09-06T18:34:39Z",
  "aliases" : [ "CVE-2026-19931" ],
  "details" : "A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given\nhostname using Negotiate authentication, when the initial request is done\nusing empty credentials. This can make user B's request get sent over user A's\npreviously authenticated connection.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-19931"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/3923520"
  }, {
    "type" : "WEB",
    "url" : "https://curl.se/docs/CVE-2026-19931.html"
  }, {
    "type" : "WEB",
    "url" : "https://curl.se/docs/CVE-2026-19931.json"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-488" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-06T18:17:20Z"
  }
}