Nimbus validated `topology.blobstore.map` against the calling subject at submission time only. The rebalance
operation accepts configuration overrides and stripped a small set of keys from them, but never re-ran that
validation, so a caller authorised to rebalance a topology could introduce a blobstore map entry naming a
blob whose ACL does not grant them access. Supervisors localise whatever key the map names, placing the
blob's contents into the topology's working directory.
The same advisory covers `listBlobs`, which performed no authorization check and passed no subject, unlike
the neighbouring `getBlobMeta` and `beginBlobDownload` operations. It therefore returned every key in the
blobstore to any caller able to reach the Nimbus Thrift port, which provides the key names that make the
above practical. On its own the disclosure is metadata only.
Mitigation
Upgrade to 3.1.0, where rebalance configuration overrides are validated exactly as submission-time
configuration is, against the rebalancing caller, and where `listBlobs` applies the configured
authorization.
Users who cannot upgrade immediately should restrict rebalance rights to trusted principals, keeping in mind
that membership of a topology's `topology.users` or `topology.groups` confers them.
Credit
The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Apache Software Foundation | Apache Storm Nimbus | unaffected |
|
No data.
No data.
No data.
Project Subscriptions
No data.
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 14 Sep 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
cvssV3_1
|
Mon, 14 Sep 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Description Nimbus validated `topology.blobstore.map` against the calling subject at submission time only. The rebalance operation accepts configuration overrides and stripped a small set of keys from them, but never re-ran that validation, so a caller authorised to rebalance a topology could introduce a blobstore map entry naming a blob whose ACL does not grant them access. Supervisors localise whatever key the map names, placing the blob's contents into the topology's working directory. The same advisory covers `listBlobs`, which performed no authorization check and passed no subject, unlike the neighbouring `getBlobMeta` and `beginBlobDownload` operations. It therefore returned every key in the blobstore to any caller able to reach the Nimbus Thrift port, which provides the key names that make the above practical. On its own the disclosure is metadata only. Mitigation Upgrade to 3.1.0, where rebalance configuration overrides are validated exactly as submission-time configuration is, against the rebalancing caller, and where `listBlobs` applies the configured authorization. Users who cannot upgrade immediately should restrict rebalance rights to trusted principals, keeping in mind that membership of a topology's `topology.users` or `topology.groups` confers them. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm. | |
| Title | Apache Storm Nimbus: Blobstore Authorization Bypass via Rebalance Configuration Overrides | |
| Weaknesses | CWE-863 | |
| References |
|
Projects
Sign in to view the affected projects.
MITRE
Status: PUBLISHED
Assigner: apache
Published:
Updated: 2026-09-14T20:03:24.941Z
Reserved: 2026-08-29T10:23:29.749Z
Link: CVE-2026-82432
Vulnrichment
No data.
NVD
Status : Deferred
Published: 2026-09-14T15:17:10.187
Modified: 2026-09-14T20:58:48.430
Link: CVE-2026-82432
Redhat
No data.
OpenCVE Enrichment
No data.