GHSA-HW7R-WM97-CF8J
Vulnerability from github – Published: 2026-09-14 15:32 – Updated: 2026-09-14 21:31Description
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.
{
"affected": [],
"aliases": [
"CVE-2026-82432"
],
"database_specific": {
"cwe_ids": [
"CWE-863"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-14T15:17:10Z",
"severity": "HIGH"
},
"details": "Description\n\nNimbus validated `topology.blobstore.map` against the calling subject at submission time only. The rebalance\noperation accepts configuration overrides and stripped a small set of keys from them, but never re-ran that\nvalidation, so a caller authorised to rebalance a topology could introduce a blobstore map entry naming a\nblob whose ACL does not grant them access. Supervisors localise whatever key the map names, placing the\nblob\u0027s contents into the topology\u0027s working directory.\n\nThe same advisory covers `listBlobs`, which performed no authorization check and passed no subject, unlike\nthe neighbouring `getBlobMeta` and `beginBlobDownload` operations. It therefore returned every key in the\nblobstore to any caller able to reach the Nimbus Thrift port, which provides the key names that make the\nabove practical. On its own the disclosure is metadata only.\n\nMitigation\n\nUpgrade to 3.1.0, where rebalance configuration overrides are validated exactly as submission-time\nconfiguration is, against the rebalancing caller, and where `listBlobs` applies the configured\nauthorization.\n\nUsers who cannot upgrade immediately should restrict rebalance rights to trusted principals, keeping in mind\nthat membership of a topology\u0027s `topology.users` or `topology.groups` confers them.\n\nCredit\n\nThe ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.",
"id": "GHSA-hw7r-wm97-cf8j",
"modified": "2026-09-14T21:31:40Z",
"published": "2026-09-14T15:32:49Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82432"
},
{
"type": "WEB",
"url": "https://lists.apache.org/thread/psy1gj77jhf9y3lhph9yz4f5fovmkz7b"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2026/09/13/12"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.