# CVE-2026-5535: FedML-AI FedML MQTT Message FileUtils.java path traversal

> Remote attackers can exploit a path traversal flaw in the MQTT message handler to read or modify arbitrary files on the system.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Apr 2026
- **Updated:** 6 Apr 2026
- **Also known as:** GHSA-x5gq-6962-7gv9

## What is CVE-2026-5535?

CVE-2026-5535 is a medium-severity path traversal vulnerability in FedML-AI FedML, published on 5 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A security flaw has been discovered in FedML-AI FedML up to 0.8.9. This impacts an unknown function of the file FileUtils.java of the component MQTT Message Handler. Performing a manipulation of the argument dataSet results in path traversal. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-5535?

It affects 1 product.


Products: Tensoropera Fedml.

## How do I fix CVE-2026-5535?

No fix has been published for CVE-2026-5535 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5535 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5535 exists.

## Other vulnerabilities in FedML-AI FedML

- [CVE-2026-5536](https://insights.sbomify.com/CVE-2026-5536/): FedML-AI FedML gRPC server grpc_server.py sendMessage deserialization (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5535 and fix it if it is affected.

What it is: CVE-2026-5535 is a medium-severity path traversal vulnerability in FedML-AI FedML, published on 5 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5535 exists.

Affected product: FedML-AI FedML. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5535/ (Markdown: https://insights.sbomify.com/CVE-2026-5535/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5535
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5535
- OSV: https://osv.dev/vulnerability/CVE-2026-5535

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5535/
Summaries are generated and may contain mistakes; the official description above is the record.