CVE-2026-42091

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

Published May 4, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-rhf7-wvw3-vjvm goshs has Cross-Origin Arbitrary File Write via Missing CSRF on PUT and Wildcard CORS
History
Type Values Removed Values Added
First Time appeared Goshs
Goshs goshs
CPEs cpe:2.3:a:goshs:goshs:*:*:*:*:*:go:*:*
Vendors & Products Goshs
Goshs goshs
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Patrickhener
Patrickhener goshs
Vendors & Products Patrickhener
Patrickhener goshs
Type Values Removed Values Added
Description 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.
Title goshs has Cross-Origin Arbitrary File Write via Missing CSRF on PUT and Wildcard CORS
Weaknesses CWE-352
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 5, 2026, 2:14 PM
Reserved
Apr 23, 2026, 7:17 PM
Status
Analyzed
Published
May 4, 2026, 6:16 PM
Modified
Oct 26, 2026, 7:10 PM