Auth bypass in Goshs
CVE-2026-40189
goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.4, goshs enforces the documented per-folder .goshs ACL/basic-auth mechanism for directory listings and file reads, but it does not enforce the same authorization checks for state-changing routes. An unauthenticated attacker can upload files with PUT, upload files with multipart POST /upload, create directories with ?mkdir, and delete files with ?delete inside a .goshs-protected directory. By deleting the .goshs file itself, the attacker can remove the folder's auth policy and then access previously protected content without credentials. This results in a critical authorization bypass affecting confidentiality, integrity, and availability. This vulnerability is fixed in 2.0.0-beta.4.
Vulnerability class: Broken Access Control
Published · last modified .
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: 0.007 (49.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.000
Affected products
- Goshs — versions 2.0.0
- Patrickhener Goshs — versions < 2.0.0-beta.4
Weakness classification (CWE)
References
- github.com/patrickhener/goshs/security/advisories/GHSA-wvhv-qcqf-f3cx (Exploit, Mitigation, Vendor Advisory)
- github.com/patrickhener/goshs/commit/f212c4f4a126556bab008f79758e21a839ef2c0f (Patch)
- github.com/patrickhener/goshs/releases/tag/v2.0.0-beta.4 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-40189?
- CVE-2026-40189 is a critical-severity vulnerability in Goshs, classified under Missing Authorization. CVSS score: 9.8/10. Published 2026-04-10.
- How severe is CVE-2026-40189?
- Critical severity. CVSS v3 base score is 9.8 out of 10.