What is CVE-2026-40884?

CVE-2026-40884 is a critical-severity vulnerability in Goshs, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-04-21.

How severe is CVE-2026-40884?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Goshs

CVE-2026-40884

goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP authentication bypass when the documented empty-username basic-auth syntax is used. If the server is started with -b ':pass' together with -sftp, goshs accepts that configuration but does not install any SFTP password handler. As a result, an unauthenticated network attacker can connect to the SFTP service and access files without a password. This vulnerability is fixed in 2.0.0-beta.6.

Vulnerability class: Broken Authentication

Published 2026-04-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (48.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.002

Affected products

Goshs — versions 2.0.0
Patrickhener Goshs — versions < 2.0.0-beta.6

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

github.com/patrickhener/goshs/security/advisories/GHSA-c29w-qq4m-2gcv (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-40884?: CVE-2026-40884 is a critical-severity vulnerability in Goshs, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-04-21.
How severe is CVE-2026-40884?: Critical severity. CVSS v3 base score is 9.8 out of 10.