CVE-2026-40876
published 2026-04-21CVE-2026-40876: goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP root escape caused by prefix-based path validation. An authenticated…
PriorityP260high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
0.44%
35.1th percentile
goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP root escape caused by prefix-based path validation. An authenticated SFTP user can read from and write to filesystem paths outside the configured SFTP root, which breaks the intended jail boundary and can expose or modify unrelated server files. The SFTP subsystem routes requests through sftpserver/sftpserver.go into DefaultHandler.GetHandler() in sftpserver/handler.go, which forwards file operations into readFile, writeFile, listFile, and cmdFile. All of those sinks rely on sanitizePath() in sftpserver/helper.go. helper.go uses a raw string-prefix comparison, not a directory-boundary check. Because of that, if the configured root is /tmp/goshsroot, then a sibling path such as /tmp/goshsroot_evil/secret.txt incorrectly passes validation since it starts with the same byte prefix. This vulnerability is fixed in 2.0.0-beta.6.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | patrickhener_goshs | 0 – 1.1.4 | — |
| github.com | patrickhener_goshs_v2 | >= 0 < 2.0.0 | 2.0.0 |
| goshs | goshs | < 2.0.0 | 2.0.0 |
| goshs | goshs | — | — |
| patrickhener | goshs | < 2.0.0-beta.6 | 2.0.0-beta.6 |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv4.08.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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VulDB
patrickhener goshs up to 2.0.0-beta.5 sftpserver/sftpserver.go DefaultHandler.GetHandler path traversal (GHSA-5h6h-7rc9-3824)
vuldb·2026-04-21·CVSS 8.7
CVE-2026-40876 [HIGH] patrickhener goshs up to 2.0.0-beta.5 sftpserver/sftpserver.go DefaultHandler.GetHandler path traversal (GHSA-5h6h-7rc9-3824)
A vulnerability classified as critical was found in patrickhener goshs up to 2.0.0-beta.5. Affected by this issue is the function DefaultHandler.GetHandler of the file sftpserver/sftpserver.go. Such manipulation leads to path traversal.
This vulnerability is listed as CVE-2026-40876. The attack may be performed from remote. There is no available exploit.
Upgrading the affected component is advised.
GHSA
SFTP root escape via prefix-based path validation in goshs
ghsa·2026-04-14
CVE-2026-40876 [HIGH] CWE-22 SFTP root escape via prefix-based path validation in goshs
SFTP root escape via prefix-based path validation in goshs
### Summary
goshs contains an SFTP root escape caused by prefix-based path validation. An authenticated SFTP user can read from and write to filesystem paths outside the configured SFTP root, which breaks the intended jail boundary and can expose or modify unrelated server files.
### Details
The SFTP subsystem routes requests through `sftpserver/sftpserver.go:99-126` into `DefaultHandler.GetHandler()` in `sftpserver/handler.go:90-112`, which forwards file operations into `readFile`, `writeFile`, `listFile`, and `cmdFile`. All of those sinks rely on `sanitizePath()` in `sftpserver/helper.go:47-59`. The vulnerable logic is:
```go
cleanPath = filepath.Clean("/" + clientPath)
if !strings.HasPrefix(cleanPath, sftpRoot) {
return "", e
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-04-21
Published