CVE-2026-42091CWE-352

goshs has Cross-Origin Arbitrary File Write via Missing CSRF on PUT and Wildcard CORS

Medium · published May 4, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
12.6
In the wild
Unconfirmed
What it is

goshs is a SimpleHTTPServer written in Go. Prior to version 2.0.2, the PUT upload handler (httpserver/updown.go) lacks the CSRF token validation that was added to the POST upload handler during the CVE-2026-40883 fix. Combined with the unconditional Access-Control-Allow-Origin: * on the OPTIONS preflight handler (httpserver/server.go), any website can write arbitrary files to a goshs instance through the victim's browser — bypassing network isolation (e.g. localhost, internal network). This issue has been patched in version 2.0.2.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00226 · 12.6th percentile
Weakness
CWE-352 · Cross-Site Request Forgery (CSRF)
Published
2026-05-04T17:24Z
EPSS history
Timeline
  • 04 MAY 17:24Z
    goshs has Cross-Origin Arbitrary File Write via Missing CSRF on PUT and Wildcard CORS
    cvelistv5