Unauthenticated file access via omitted SFTP password handler
Published Apr 21, 2026 · Updated Apr 21, 2026
SFTP authentication bypass in goshs before 2.0.0-beta.6 allows remote attackers to read and alter files without credentials. The SFTP setup splits -b ':pass' into an empty username and nonempty password, then requires both fields to be nonempty before installing PasswordHandler. When SFTP and the documented empty-username basic-auth form are enabled without a key handler, the service accepts unauthenticated sessions, exposing the configured SFTP root to reads, uploads, renames, and deletions.
Summary
What happened
SFTP authentication bypass in goshs before 2.0.0-beta.6 allows remote attackers to read and alter files without credentials. The SFTP setup splits -b ':pass' into an empty username and nonempty password, then requires both fields to be nonempty before installing PasswordHandler. When SFTP and the documented empty-username basic-auth form are enabled without a key handler, the service accepts unauthenticated sessions, exposing the configured SFTP root to reads, uploads, renames, and deletions.
The record
- CVE
- CVE-2026-40884
- Published
- Apr 21, 2026
- Updated
- Apr 21, 2026
- Vendor
- Patrick Hener
- Product
- goshs
- Classifications
- CWE-306, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 21, 2026CVE publishedPublication date reported by the CVE source.
- Apr 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.0.0-beta.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Vendor advisory SFTP proof-of-conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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