CVE-2026-34745
An unauthenticated attacker can exploit the checkSum parameter to write arbitrary files with attacker-controlled content to any writable path on the server filesystem.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.62%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- EPSS
- 0.62% probability · 48th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Affected
- shaneisrael/fireshare
- Source
- security-advisories@github.com
References
- https://github.com/ShaneIsrael/fireshare/commit/b76915607924756e6fa1a5f6c8823c38d611fb24Patch
- https://github.com/ShaneIsrael/fireshare/pull/520Issue Tracking, Patch
- https://github.com/ShaneIsrael/fireshare/releases/tag/v1.5.3Release Notes
- https://github.com/ShaneIsrael/fireshare/security/advisories/GHSA-fvvp-rj8g-c7gcExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.