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

Critical 9.1 Published 2 Apr 2026 Updated 2 Apr 2026

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

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

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

Which versions are affected by CVE-2026-34745?

It affects 1 product.

Products include 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.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-34745 being exploited?

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

Sources

Also known as GHSA-fvvp-rj8g-c7gc.