CVE-2026-82431: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-45m3-3j6g-xv67
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CVSS 9.8
CWE-863
Published
Advisory Summary

CVE-2026-82431 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (CWE-863: Incorrect Authorization) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-82431 at a Glance

CVE Identifier CVE-2026-82431
GHSA Identifier GHSA-45m3-3j6g-xv67
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-863: Incorrect Authorization
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-2026-82431

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-2026-82431, 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-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the 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

Description `SimpleACLAuthorizer` evaluated the user-level command set by returning early when `nimbus.users` was empty, before `nimbus.groups` was considered. An operator who restricted cluster access by group alone, leaving `nimbus.users` unset, therefore received no restriction at all: every authenticated principal was permitted every user-level operation, including `submitTopology`, `beginFileUpload` and `getNimbusConf`. `docs/SECURITY.md` presents `nimbus.groups` as a supported way to lock down a cluster, so a deployment following the documentation could believe it was restricted while it was not. The failure is silent; nothing in the logs or the configuration indicates that the group list is being ignored. Both lists left empty continues to mean that no restriction is configured, which is the shipped default and is unchanged. Mitigation Upgrade to 3.1.0, where `nimbus.groups` is evaluated whether or not `nimbus.users` is set. Users who cannot upgrade immediately should additionally populate `nimbus.users` with the intended principals, since a non-empty user list causes the group list to be evaluated on affected versions. Operators should review Nimbus access logs for operations by principals outside the intended groups. Note that after upgrading, a cluster configured with `nimbus.groups` alone becomes restrictive for the first time. This includes `NimbusClient`, which calls `getLeader` on every connection, so clients outside the configured groups will begin to be refused. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

References

NVD — CVE-2026-82431 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-82431
lists.apache.org/thread/s335qxb6woqb... WEB
https://lists.apache.org/thread/s335qxb6woqb35ho3fpq7toytsz1gpts
Software Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/09/13/11

Frequently Asked Questions

What is CVE-2026-82431?
CVE-2026-82431 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-863: Incorrect Authorization.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-82431?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-82431?
CVE-2026-82431 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-2026-82431?
CVE-2026-82431 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check Maven dependencies for CVE-2026-82431?
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-45m3-3j6g-xv67",
  "modified" : "2026-09-14T21:31:40Z",
  "published" : "2026-09-14T15:32:49Z",
  "aliases" : [ "CVE-2026-82431" ],
  "details" : "Description\n\n`SimpleACLAuthorizer` evaluated the user-level command set by returning early when `nimbus.users` was empty,\nbefore `nimbus.groups` was considered. An operator who restricted cluster access by group alone, leaving\n`nimbus.users` unset, therefore received no restriction at all: every authenticated principal was permitted\nevery user-level operation, including `submitTopology`, `beginFileUpload` and `getNimbusConf`.\n\n`docs/SECURITY.md` presents `nimbus.groups` as a supported way to lock down a cluster, so a deployment\nfollowing the documentation could believe it was restricted while it was not. The failure is silent; nothing\nin the logs or the configuration indicates that the group list is being ignored.\n\nBoth lists left empty continues to mean that no restriction is configured, which is the shipped default and\nis unchanged.\n\nMitigation\n\nUpgrade to 3.1.0, where `nimbus.groups` is evaluated whether or not `nimbus.users` is set.\n\nUsers who cannot upgrade immediately should additionally populate `nimbus.users` with the intended\nprincipals, since a non-empty user list causes the group list to be evaluated on affected versions.\nOperators should review Nimbus access logs for operations by principals outside the intended groups.\n\nNote that after upgrading, a cluster configured with `nimbus.groups` alone becomes restrictive for the first\ntime. This includes `NimbusClient`, which calls `getLeader` on every connection, so clients outside the\nconfigured groups will begin to be refused.\n\nCredit\n\nThe ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.",
  "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-2026-82431"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread/s335qxb6woqb35ho3fpq7toytsz1gpts"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2026/09/13/11"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-14T15:17:10Z"
  }
}