Advisory [CVE-2026-82426] Apache Storm PMC: Description Nimbus accepted the `uploadedJarLocation` argument of `submitTopology` / `submitTopologyWithOpts` as a server-side path and opened it directly, without checking that it referred to a file the caller had actually uploaded

Nimbus accepted the `uploadedJarLocation` argument of `submitTopology` / `submitTopologyWithOpts` as a server-side path and opened it directly, without checking that it referred to a file the caller had

actually uploaded. The intended flow is that a client first calls `beginFileUpload`, which returns a path

inside the Nimbus inbox, and uploads the jar in chunks to that location; nothing bound submission to that flow, and the `uploaders` map populated by `beginFileUpload` was never consulted at submit time.

An authenticated user with topology submission rights could therefore submit any path readable by the Nimbus daemon user as their topology jar.

Nimbus copied the file into the topology's jar blob, and the blob ACL grants the submitting subject read access, so the contents could then be retrieved with the

ordinary blob download RPCs. Candidate targets include the Nimbus Kerberos keytab, Thrift and UI TLS

private keys, and `storm.yaml` with the ZooKeeper authentication payload. turns an ordinary tenant into a cluster administrator.

In a deployment configured as the documentation recommends, submission is available to every authenticated principal when `nimbus.users` is unset, so no elevated privilege is required.

Affected product named by the advisory: Apache Storm PMC.