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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Shaneisrael Fireshare
cpe:2.3:a:shaneisrael:fireshare:*:*:*:*:*:*:*:*
|
— |
1.5.3
|
References 4
https://github.com/ShaneIsrael/fireshare/commit/b76915607924756e6fa1a5f6c8823c3…
security-advisories@github.com
https://github.com/ShaneIsrael/fireshare/pull/520
security-advisories@github.com
https://github.com/ShaneIsrael/fireshare/releases/tag/v1.5.3
security-advisories@github.com
https://github.com/ShaneIsrael/fireshare/security/advisories/GHSA-fvvp-rj8g-c7gc
security-advisories@github.com