# CVE-2026-17459: perwendel spark SparkJava ExternalResourceHandler.jav staticFiles.externalLocation symlink

> Attackers can read arbitrary files via symlink following in SparkJava's external static file handler, requiring specific configuration.

- **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:** 26 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** GHSA-cjfh-hv3c-xcfg

## What is CVE-2026-17459?

CVE-2026-17459 is a medium-severity path traversal vulnerability in perwendel spark, published on 26 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was determined in perwendel spark up to 2.9.4. This vulnerability affects the function staticFiles.externalLocation of the file src/main/java/spark/resource/ExternalResourceHandler.jav of the component SparkJava. Executing a manipulation can lead to symlink following. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-61 (UNIX Symbolic Link (Symlink) Following), CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-17459?


## How do I fix CVE-2026-17459?

No fix has been published for CVE-2026-17459 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-17459 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-17459 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-17459 and fix it if it is affected.

What it is: CVE-2026-17459 is a medium-severity path traversal vulnerability in perwendel spark, published on 26 Jul 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-2026-17459 exists.

Affected product: perwendel spark. 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-2026-17459/ (Markdown: https://insights.sbomify.com/CVE-2026-17459/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-17459
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-17459
- OSV: https://osv.dev/vulnerability/CVE-2026-17459

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-17459/
Summaries are generated and may contain mistakes; the official description above is the record.