Apache Storm Nimbus up to 3.0.x input validation

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Apache Storm Nimbus up to 3.0.x. Impacted is an unknown function of the component Nimbus. Performing a manipulation results in input validation. This vulnerability is identified as CVE-2026-82441. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Apache Storm Nimbus up to 3.0.x. This affects an unknown functionality of the component Nimbus. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Description A submitted topology carries two lists of blobstore keys, `dependency_jars` and `dependency_artifacts`, which the client fills in after uploading the corresponding blobs. Nimbus performed no validation of their contents on the submission path, yet acts on them in two places. During cleanup of a finished topology, Nimbus deletes the keys named in those lists, and the deletion is performed as the Nimbus subject, for which the blobstore short-circuits its ACL check. A submitter who listed a key belonging to another topology, such as its `-stormjar.jar`, could therefore cause that blob to be deleted when their own topology was cleaned up. Separately, on acquiring leadership a Nimbus compares the dependency keys of all active topologies against the blobstore contents and surrenders leadership if any is missing. A single key that does not exist, on a single active topology, therefore causes every Nimbus to acquire leadership, surrender it and requeue indefinitely, leaving the cluster without a leader and unable to schedule, clean up or accept submissions. Mitigation Upgrade to 3.1.0, where a submission is refused unless every entry in both lists is a dependency blob key and exists in the blobstore. Note that this validates new submissions only; a topology stored by an affected version with an invalid list is unaffected by the upgrade. An operator whose cluster is failing to retain a leader should inspect the Nimbus log for the dependency keys reported as missing and remove or resubmit the topology naming them. Users who cannot upgrade immediately should restrict topology submission to trusted principals. Credit This issue was discovered by rzo1 while investigating an unrelated blobstore defect.

It is possible to read the advisory at lists.apache.org. This vulnerability is uniquely identified as CVE-2026-82441 since 08/29/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/14/2026).

Upgrading to version 3.1.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-77486). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• Apache

Name

• Storm Nimbus

Version

• 3.0

License

• open-source

Website

• Vendor: https://www.apache.org/

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