Vulnerability DatabaseCVE-2026-123570
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CVE-2026-123570
Published:November 08, 2026
Updated:November 09, 2026
The DNS wire-format message parser in hickory-proto (Hickory DNS) 0.18 before 0.26.2 preallocates record vectors sized by the untrusted ANCOUNT, NSCOUNT, and ARCOUNT header fields before reading record data. Remote attackers can send a UDP datagram, or a spoofed response to a client/resolver, with these counts set to 65535, forcing about 18MB of allocation per message.
Affected Packages
https://github.com/hickory-dns/hickory-dns.git (GITHUB):
Affected version(s) >=0.2.0 <v0.26.2 || >=0.3.0 <v0.26.2 || =0.4.0 <v0.26.2 || >=0.5.0 <v0.26.2 || =0.6.0 <v0.26.2 || >=0.7.0 <v0.26.2 || >=0.8.0 <v0.26.2 || >=0.9.0 <v0.26.2 || >=0.10.0 <v0.26.2 || =0.11.0 <v0.26.2 || =c0.12.0 <v0.26.2 || =r0.7.0 <v0.26.2 || >=r0.8.0 <v0.26.2 || >=r0.9.0 <v0.26.2 || >=r0.10.0 <v0.26.2 || >=r0.11 <v0.26.2 || =r0.12_cs0.17 <v0.26.2 || =v0.13.0 <v0.26.2 || =v0.14.0 <v0.26.2 || =cs0.15.0 <v0.26.2 || >=cs0.16 <v0.26.2 || >=0.18.0.alpha.2 <v0.26.2 || >=0.19.0 <v0.26.2 || =v0.19.7 <v0.26.2 || >=v0.20.0-alpha.1 <v0.26.2 || >=v0.21.0-alpha.1 <v0.26.2 || >=v0.22.0 <v0.26.2 || >=v0.23.0-alpha.1 <v0.26.2 || >=v0.24.0 <v0.26.2 || >=v0.25.0-alpha.1 <v0.26.2 || >=v0.26.0-alpha.1 <v0.26.2 || =resolver.0.4.0 <v0.26.2 || =r0.5.0 <v0.26.2 || =r0.6.0 <v0.26.2
Fix Suggestion:
Update to version v0.26.2
hickory-proto (RUST):
Affected version(s) >=0.24.0 <0.26.2 || >=0.25.0-alpha.1 <0.26.2 || >=0.26.0-alpha.1 <0.26.2
Fix Suggestion:
Update to version 0.26.2
Related Resources (4)
https://nvd.nist.gov/vuln/detail/CVE-2026-123570
https://www.vulncheck.com/advisories/hickory-dns-from-0.18-before-0.26.2-memory-amplification-dos-via-rr-counts
https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/123xxx/CVE-2026-123570.json
https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-67wc-6jq8-ghrc
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CVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Uncontrolled Resource Consumption
CWE-400
EPSS
Base Score:
0.41