CVE-2026-82432
CVE-2026-82432 is a CWE-863 vulnerability. O3 Security confirms whether CVE-2026-82432 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Description Nimbus validated `topology.blobstore.map` against the calling subject at submission time only. The rebalance operation accepts configuration overrides and stripped a small…
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-82432.
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-82432 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-82432 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-82432. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-82432 in your dependencies?
O3 detects CVE-2026-82432 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.