# CVE-2026-34745: Unauthenticated Path Traversal Arbitrary File Write in /api/uploadChunked/public

> Unauthenticated attackers can write arbitrary files to the server via path traversal in the public upload endpoint, potentially leading to code execution.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Apr 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-fvvp-rj8g-c7gc

## What is CVE-2026-34745?

CVE-2026-34745 is a critical path traversal vulnerability in ShaneIsrael fireshare, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Fireshare facilitates self-hosted media and link sharing. Prior to version 1.5.3, the fix for CVE-2026-33645 was applied to the authenticated /api/uploadChunked endpoint but was not applied to the unauthenticated /api/uploadChunked/public endpoint in the same file (app/server/fireshare/api.py). An unauthenticated attacker can exploit the checkSum parameter to write arbitrary files with attacker-controlled content to any writable path on the server filesystem. This issue has been patched in version 1.5.3.

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

## Which versions are affected by CVE-2026-34745?

It affects 1 product.


Products: Shaneisrael Fireshare.

## How do I fix CVE-2026-34745?

No fix has been published for CVE-2026-34745 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34745 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34745 exists.

## Other vulnerabilities in ShaneIsrael fireshare

- [CVE-2025-67728](https://insights.sbomify.com/CVE-2025-67728/): Fireshare Public Uploads feature is vulnerable to OS Command Injection (RCE) (critical 9.8)
- [CVE-2026-33645](https://insights.sbomify.com/CVE-2026-33645/): Fireshare has Path Traversal Arbitrary File Write in `/api/uploadChunked` (high 7.1)
- [CVE-2025-55476](https://insights.sbomify.com/CVE-2025-55476/): SQL injection in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34745 and fix it if it is affected.

What it is: CVE-2026-34745 is a critical path traversal vulnerability in ShaneIsrael fireshare, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34745 exists.

Affected product: ShaneIsrael fireshare. 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-2026-34745/ (Markdown: https://insights.sbomify.com/CVE-2026-34745/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34745
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34745
- OSV: https://osv.dev/vulnerability/CVE-2026-34745

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34745/
Summaries are generated and may contain mistakes; the official description above is the record.