SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-40189

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.

CRITICAL 9.3EPSS 0.64%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.64%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0
9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.64% probability · 49th percentile
CISA KEV
Not listed
Weakness
CWE-862
Affected
goshs/goshs
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.