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Fencer Intel
high 7.8

CVE-2026-82427 json

Apache Storm Nimbus: Path Traversal as the Supervisor User via Unsanitised Blobstore Map Local Name

published last mo. modified last mo. also EUVD-2026-77530

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

Description

A topology's `topology.blobstore.map` lets the submitter choose a local name for each blob that the supervisor localises. That name was used to build a path under the topology's working directory without normalisation, in both `AsyncLocalizer` and `Container.createBlobstoreLinks`, and the symlink helper force-deletes whatever already exists at the target before creating the link.

A submitter could therefore use `../` segments to direct that delete-and-symlink operation at an arbitrary path, as the supervisor user, on every node the topology is scheduled onto. The consequences include recursive deletion of supervisor-owned content and planting a symlink that causes a subsequent worker launch to execute attacker-chosen code as another tenant's operating-system user, which defeats the isolation that `supervisor.run.worker.as.user` is intended to provide.

Mitigation

Upgrade to 3.1.0, where the resolved target must lie inside the expected root at both call sites.

Users who cannot upgrade immediately should restrict topology submission to trusted principals, and may reject submissions whose `topology.blobstore.map` entries contain path separators or `..` segments before they reach Nimbus.

Credit

The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Patch / fix

  • Apache Software Foundation Apache Storm Nimbus 3.1.0

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Apache Software Foundation Apache Storm Nimbus

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.