CVE-2026-123570

high

Description

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.

References

https://www.vulncheck.com/advisories/hickory-dns-from-0.18-before-0.26.2-memory-amplification-dos-via-rr-counts

https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-67wc-6jq8-ghrc

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-119455

Details

Source: Mitre, NVD

Published: 2026-11-08

Updated: 2026-11-09

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

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

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00409