Vulnerability · Published Apr 2, 2026 · Assigned by GitHub_M

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

Critical 9.1

In plain English

A critical-severity path traversal in fireshare from ShaneIsrael. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical

Exploit odds (30 days)0.6%top 49.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
ShaneIsrael	fireshare	< 1.5.3

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

References

https://github.com/ShaneIsrael/fireshare/security/advisories/GHSA-fvvp-rj8g-c7gc x_refsource_CONFIRM
https://github.com/ShaneIsrael/fireshare/pull/520 x_refsource_MISC
https://github.com/ShaneIsrael/fireshare/commit/b76915607924756e6fa1a5f6c8823c38d611fb24 x_refsource_MISC
https://github.com/ShaneIsrael/fireshare/releases/tag/v1.5.3 x_refsource_MISC