CVE-2026-33645 — Fireshare has Path Traversal Arbitrary File Write in `/api/uploadChunked`
Fireshare facilitates self-hosted media and link sharing. In version 1.5.1, an authenticated path traversal vulnerability in Fireshare’s chunked upload endpoint allows an attack…
Published: 2026-03-26 · CVSS: 7.1 · CVSS 3.1
Fireshare facilitates self-hosted media and link sharing. In version 1.5.1, an authenticated path traversal vulnerability in Fireshare’s chunked upload endpoint allows an attacker to write arbitrary files outside the intended upload directory. The `checkSum` multipart field is used directly in filesystem path construction without sanitization or containment checks. This enables unauthorized file writes to attacker-chosen paths writable by the Fireshare process (e.g., container `/tmp`), violating integrity and potentially enabling follow-on attacks depending on deployment. Version 1.5.2 fixes the issue.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7