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No exploitation reported

CVE-2026-82440

Apache Storm Nimbus: Submitter-Controlled Class Instantiation in Nimbus via a Fail-Open Scheduler Strategy Allowlist

No exploitation reported by the sources we read.

  • Published2026-11-09
  • WeaknessCWE-470

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Description Nimbus instantiates the class named by a topology's `topology.scheduler.strategy` when scheduling it. The allowlist intended to constrain that choice, `nimbus.scheduler.strategy.class.whitelist`, was treated as "allow any class" when unset, and it had no entry in the shipped `defaults.yaml`, so unset was the shipped state. An authenticated submitter could therefore cause Nimbus to instantiate any class on the Nimbus classpath that has a no-argument constructor. Storm's own production artifacts contain classes with side effects suitable for this: instantiating `org.apache.storm.testing.InProcessZookeeper` starts a ZooKeeper server with its own threads and sockets and nothing closes it, and `org.apache.storm.LocalCluster` behaves similarly. Repeated submissions therefore consume threads, sockets and memory in the most privileged daemon in the cluster. Mitigation Upgrade to 3.1.0, where an unset allowlist means the strategies shipped with Storm rather than any class. Note that this is a behaviour change: a cluster running an out-of-tree scheduler strategy without an explicit allowlist will have those topologies refused until the class is added to `nimbus.scheduler.strategy.class.whitelist`. The rejection message names the refused class and the configuration key. Users who cannot upgrade immediately should set `nimbus.scheduler.strategy.class.whitelist` explicitly to the strategies they intend to permit.

Timeline

dates in UTC
  1. 2026-11-0910:01CVE publishedCNA

Versions per branch

Products declared by the CNA

As apache, the CNA that assigned this CVE, declared them in the CVE record; versions as written. NVD lists no product for this CVE yet: this is the only product data so far.

  • Apache Software Foundation Apache Storm Nimbusother versions: not affected

    package org.apache.storm:storm-clienthttps://repo.maven.apache.org/maven2

    Affected
    • ≥ 3.0.0, < 3.1.0fixed in 3.1.0semver

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-09

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-82440 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Published
2026-11-09
Last Modified
2026-11-12
NVD status
Deferred
GitHub Advisory
GHSA-p7mh-274j-m4mq

Frequently asked questions

What is CVE-2026-82440?

Description Nimbus instantiates the class named by a topology's `topology.scheduler.strategy` when scheduling it. The allowlist intended to constrain that choice, `nimbus.scheduler.strategy.class.whitelist`, was treated as "allow any class" when unset, and it had no entry in the shipped `defaults.yaml`, so unset was the shipped state. An authenticated submitter could therefore cause Nimbus to instantiate any class on the Nimbus classpath that has a no-argument constructor. Storm's own production artifacts contain classes with side effects suitable for this: instantiating `org.apache.storm.testing.InProcessZookeeper` starts a ZooKeeper server with its own threads and sockets and nothing closes it, and `org.apache.storm.LocalCluster` behaves similarly. Repeated submissions therefore consume threads, sockets and memory in the most privileged daemon in the cluster. Mitigation Upgrade to 3.1.0, where an unset allowlist means the strategies shipped with Storm rather than any class. Note that this is a behaviour change: a cluster running an out-of-tree scheduler strategy without an explicit allowlist will have those topologies refused until the class is added to `nimbus.scheduler.strategy.class.whitelist`. The rejection message names the refused class and the configuration key. Users who cannot upgrade immediately should set `nimbus.scheduler.strategy.class.whitelist` explicitly to the strategies they intend to permit.

Is CVE-2026-82440 actively exploited?

Active exploitation of CVE-2026-82440 has not been confirmed. Its EPSS score was 0.2% on 2026-11-11, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-82440?

CVE-2026-82440 has a CVSS v3 base score of 8.1 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H.

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