CVE-2026-82434 — Apache Storm Nimbus, Apache Storm Client: Disclosure of the Topology ZooKeeper Credential to Read-Only Users and to Logs
Description When ZooKeeper authentication is configured, Storm deliberately retains `storm.zookeeper.topology.auth.payload` in the topology configuration, because workers need it. Nimbus then served that configuration verbatim to any caller holding read-only topology permissions, so a user whose only grant was the ability to view a topology received its ZooKeeper credential. That credential is not read-only. The cluster state implementation uses write-capable ACLs for worker heartbeats, backpressure and error state, so a recipient can forge or remove that state for the topology concerned. It is not a write credential on assignments. The same advisory covers the submission client, which logged the generated payload at INFO on every submission that generated one, and the SASL handlers, which logged it at DEBUG. The credential therefore also reached any log aggregation or support bundle collected from the cluster. Mitigation Upgrade to 3.1.0, where the payload is removed from the configuration served to read-only callers and is no longer written to logs. Users who cannot upgrade immediately should rotate `storm.zookeeper.topology.auth.payload` for existing topologies, review retained logs and support bundles for the value, and restrict read-only topology permissions to trusted principals. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Apache Storm Client, Apache Software Foundation Apache Storm Nimbus).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Apache Software Foundation | Apache Storm Client | ≥ 3.0.0 and < 3.1.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Apache Software Foundation | Apache Storm Nimbus | ≥ 3.0.0 and < 3.1.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 10.0 | CVSS 4.0 | Critical | — | — | security@apache.org via NIST National Vulnerability Database |
| 10.0 | CVSS 4.0 | Critical | — | — | apache via CVE Program (cve.org) e CISA ADP |
| 6.5 | CVSS 3.1 | Medium | 2.8 | 3.6 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 6.5 | CVSS 3.1 | Medium | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · apache software foundation/apache storm nimbus, apache software foundation/apache storm client
- SSVC assessment updated
- Record published
- CVSS changed · 6.5
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-82431 Apache Storm Client: Authorization Bypass When nimbus.groups Is Configured Without nimbus.users Sep 14, 2026
- High CVE-2026-82432 Apache Storm Nimbus: Blobstore Authorization Bypass via Rebalance Configuration Overrides Sep 14, 2026
- Medium CVE-2026-82433 Apache Storm Nimbus, Apache Storm UI: Disclosure of Unredacted Daemon Configuration via Nimbus and the UI Sep 14, 2026
- High CVE-2026-82428 Apache Storm Client: Cross-Tenant Dependency Jar Substitution via Predictable Blob Keys Sep 14, 2026
- Medium CVE-2026-82426 Apache Storm Nimbus: Arbitrary File Read on Nimbus via Unvalidated Uploaded Jar Location Sep 14, 2026
- High CVE-2026-82427 Apache Storm Nimbus: Path Traversal as the Supervisor User via Unsanitised Blobstore Map Local Name Sep 14, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-82434 is "Apache Storm Nimbus, Apache Storm Client: Disclosure of the Topology ZooKeeper Credential to Read-Only Users and to Logs", rated Medium. It affects Apache Storm Client (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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