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StormApplication · Apache

CVE-2026-35565

MEDIUM · 5.4 CVSS v3.1 Published 2026-04-13
Fix available
A fix is available. Upgrade to 2.8.6 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Stored Cross-Site Scripting (XSS) via Unsanitized Topology Metadata in Apache Storm UI Versions Affected: before 2.8.6 Description: The Storm UI visualization component interpolates topology metadata including component IDs, stream names, and grouping values directly into HTML via innerHTML in parseNode() and parseEdge() without sanitization at any layer. An authenticated user with topology submission rights could craft a topology containing malicious HTML/JavaScript in component identifiers (e.g., a bolt ID containing an onerror event handler). This payload flows through Nimbus → Thrift → the Visualization API → vis.js tooltip rendering, resulting in stored cross-site scripting.  In multi-tenant deployments where topology submission is available to less-trusted users but the UI is accessed by operators or administrators, this enables privilege escalation through script execution in an admin's browser session. Mitigation: 2.x users should upgrade to 2.8.6. Users who cannot upgrade immediately should monkey-patch the parseNode() and parseEdge() functions in the visualization JavaScript file to HTML-escape all API-supplied values including nodeId, :capacity, :latency, :component, :stream, and :grouping before interpolation into tooltip HTML strings, and should additionally restrict topology submission to trusted users via Nimbus ACLs as a defense-in-depth measure. A guide on how to do this is available in the release notes of 2.8.6. Credit: This issue was discovered while investigating another report by K.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Stored XSS vulnerability in Apache Storm UI where the visualization component uses innerHTML to render topology metadata (component IDs, stream names, grouping values) from parseNode() and parseEdge() functions without sanitization. Authenticated users with topology submission rights can inject malicious HTML/JavaScript (e.g., onerror event handlers) that executes when administrators view the topology in the UI.

MitigationUpgrade to Apache Storm 2.8.6 or monkey-patch parseNode() and parseEdge() to HTML-escape all API-supplied values before DOM insertion; additionally restrict topology submission via Nimbus ACLs as defense-in-depth.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
StormApplication
Affected:>= 2.0.0, < 2.8.6

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Apache Storm version
    Run 'storm version' command or inspect the storm-core JAR file version in the Storm lib directory
    Affected if Version is 2.0.0 through 2.8.5 (any version >= 2.0.0 and < 2.8.6)
  2. Verify Storm UI is accessible
    Confirm the Storm web UI is accessible on the configured port (typically 8080)
    Affected if Storm UI is exposed to users who can submit topologies or view topology visualizations
  3. Inspect Nimbus ACL configuration
    Examine the storm.yaml configuration file for nimbus.authorizer settings and any defined ACLs
    Affected if No ACLs are configured, or ACLs permit untrusted users to submit topologies
  4. Review topology submission access
    Check if users other than trusted administrators have topology submission rights via Nimbus ACLs
    Affected if Untrusted or low-privilege users can submit topologies to the Storm cluster

You are affected if your Storm version is >= 2.0.0 and < 2.8.6 AND the UI is accessible to users who can submit topologies without proper ACL restrictions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.8.6 or later
Fixed in 2.8.6
Interim mitigation

Upgrade to Apache Storm 2.8.6 or monkey-patch parseNode() and parseEdge() to HTML-escape all API-supplied values before DOM insertion; additionally restrict topology submission via Nimbus ACLs as defense-in-depth.

Recommended fix High confidence

2.8.6

  1. Download Apache Storm version 2.8.6 from the official Apache Storm distribution (storm.apache.org)
  2. Stop all running Storm services (Nimbus, Supervisors, Workers, Storm UI)
  3. Back up your current Storm configuration and any custom settings
  4. Replace the existing Storm installation with version 2.8.6 files
  5. Restore your backed-up configuration files to the new installation
  6. Restart Storm services in the correct order: Zookeeper (if embedded), Nimbus, Supervisors, Workers, then Storm UI
  7. Verify the upgrade by logging into Storm UI and confirming version 2.8.6 is displayed
  8. Test topology submission to confirm normal operation

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Storm Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,980
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-35565 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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