CVE-2026-35565 Apache Storm UI: Stored Cross-Site Scripting (XSS) via Unsanitized Topology Metadata in Storm UI
Authenticated users can inject malicious scripts via topology metadata, leading to code execution and privilege escalation in admin browsers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-35565?
CVE-2026-35565 is a medium-severity cross-site scripting vulnerability in Apache Storm UI, published on 13 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-35565?
2 open source packages ship an affected version, including org.apache.storm:storm-webapp. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.apache.storm:storm-webapp Maven | All versions | 2.8.6 |
org.apache.storm:storm-webapp Maven | All versions | 2.8.6 |
Products include Apache Storm.
How do I fix CVE-2026-35565?
Upgrade org.apache.storm:storm-webapp to 2.8.6 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-35565 being exploited?
There is no known exploitation of CVE-2026-35565 in the wild and no public exploit code.
Other vulnerabilities in Apache Storm UI
- CVE-2021-38294 Shell Command Injection Vulnerability in Nimbus Thrift Server
- CVE-2021-40865 Unsafe Pre-Authentication Deserialization In Workers
- CVE-2018-11779 Deserialization of Untrusted Data in Apache Storm
- CVE-2015-3188 Apache Storm remote code execution vulnerability
- CVE-2026-35337 Apache Storm Client: RCE through Unsafe Deserialization via Kerberos TGT Credential Handling
Sources
Also known as GHSA-f2hp-qw27-8wfq.