CVE Catalog

CVE-2026-42091

MediumCVSS 6.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

6th percentile - higher than 6% of all known CVEs

Summary

In goshs (a SimpleHTTPServer written in Go) prior to version 2.0.2, the PUT upload handler lacks the CSRF token validation added to the POST handler in the CVE-2026-40883 fix. Combined with the unconditional Access-Control-Allow-Origin: * on the OPTIONS preflight handler, any website can write arbitrary files to a goshs instance through the victim's browser, bypassing network isolation.

Risk Assessment

An attacker can remotely write arbitrary files to a goshs instance via the victim's browser, including on localhost or internal networks. This may lead to file overwrite, injection of malicious content, or further escalation.

Recommendation

Update goshs to version 2.0.2 or later. Until then, consider restricting access to the goshs instance and disabling or tightening CORS headers.

Other vulnerabilities in goshs

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS