CVE-2026-82426: Apache Storm Nimbus: Arbitrary File Read on Nimbus via Unvalidated Uploaded Jar Location
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.4%
EPSS score, percentile 36.6 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 6.5 Medium
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- from 3.0.0 to before 3.1.0
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 3.0.0 to before 3.1.0 |
Versions not listed are: unaffected.
Source: CVE List, as of . About the data.
About this vulnerability
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. 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; noth…
Summary: CVE record, as of .
- CISA has not added CVE-2026-82426 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 14 Sep 2026.
- The CVE record carries a CVSS v3.1 base score of 6.5 (Medium), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.4% (percentile 36.6), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
- The credits in the CVE record name Anthropic (Claude) as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
Apache Storm Nimbus: Arbitrary File Read on Nimbus via Unvalidated Uploaded Jar Location
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. 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. Possession of the Nimbus keytab 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. Mitigation Upgrade to 3.1.0, where the submitted location is canonicalised and must resolve inside the Nimbus inbox. Users who cannot upgrade immediately should restrict topology submission to trusted principals via `nimbus.users` or `nimbus.groups`, and should treat any file readable by the Nimbus daemon user as potentially exposed to submitters: rotate the Nimbus keytab and any TLS private keys or ZooKeeper credentials reachable from that account. Local mode is unaffected. Credit Independently reported to the Apache Storm PMC by n0mi1k, with a proof of concept. Also found by the ASF using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Source: CVE List, as of . About the data.
Weakness
CWE-22
- CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published |
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