CVE-2026-123570

Public on 2026-11-08
Modified on 2026-11-12
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.
Severity
Important severity
Important
See what this means
CVSS v3 Base Score
7.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2023 aardvark-dns Pending Fix
Amazon Linux 2027 Preview aardvark-dns Pending Fix
Amazon Linux 2 - Aws-nitro-enclaves-cli Extra aws-nitro-enclaves-cli Pending Fix
Amazon Linux 2023 aws-nitro-enclaves-cli Pending Fix
Amazon Linux 2027 Preview aws-nitro-enclaves-cli Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

FAQs regarding Amazon Linux ALAS/CVE Severity Red Hat: CVE-2026-123570 Mitre: CVE-2026-123570