CVE-2026-40876: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in patrickhener goshs
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.
AI Analysis
Technical Summary
The goshs SimpleHTTPServer's SFTP subsystem improperly limits pathname access due to prefix-based path validation in sanitizePath(). This allows an authenticated SFTP user to bypass the intended root jail by accessing filesystem paths that share the same prefix but are outside the configured root directory. For example, if the root is /tmp/goshsroot, paths like /tmp/goshsroot_evil/secret.txt are incorrectly allowed. This vulnerability affects all versions before 2.0.0-beta.6 and is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory).
Potential Impact
An authenticated SFTP user can read and write files outside the designated SFTP root directory, potentially exposing or modifying unrelated server files. This breaks the security boundary intended to isolate SFTP operations, leading to high confidentiality, integrity, and availability impacts as indicated by the CVSS 8.7 score.
Mitigation Recommendations
This vulnerability is fixed in goshs version 2.0.0-beta.6. Users should upgrade to this version or later to remediate the issue. No official patch or workaround is provided for earlier versions. Patch status is not explicitly confirmed beyond the fixed version; therefore, verify with the vendor for the latest remediation guidance.
CVE-2026-40876: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in patrickhener goshs
Description
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The goshs SimpleHTTPServer's SFTP subsystem improperly limits pathname access due to prefix-based path validation in sanitizePath(). This allows an authenticated SFTP user to bypass the intended root jail by accessing filesystem paths that share the same prefix but are outside the configured root directory. For example, if the root is /tmp/goshsroot, paths like /tmp/goshsroot_evil/secret.txt are incorrectly allowed. This vulnerability affects all versions before 2.0.0-beta.6 and is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory).
Potential Impact
An authenticated SFTP user can read and write files outside the designated SFTP root directory, potentially exposing or modifying unrelated server files. This breaks the security boundary intended to isolate SFTP operations, leading to high confidentiality, integrity, and availability impacts as indicated by the CVSS 8.7 score.
Mitigation Recommendations
This vulnerability is fixed in goshs version 2.0.0-beta.6. Users should upgrade to this version or later to remediate the issue. No official patch or workaround is provided for earlier versions. Patch status is not explicitly confirmed beyond the fixed version; therefore, verify with the vendor for the latest remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-15T15:57:41.718Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e7d78519fe3cd2cdf5b319
Added to database: 4/21/2026, 8:01:09 PM
Last enriched: 4/21/2026, 8:16:40 PM
Last updated: 4/22/2026, 6:07:14 AM
Views: 9
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