Bug 2568817 (CVE-2026-123570)

Summary: CVE-2026-123570 hickory-proto: hickory-proto: Denial of Service via excessive memory allocation in DNS parser
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: dbosanac, jcantril, jlanda, jreimann, kshier, mdessi, mrizzi, pcattana, rbobbitt, rhel-process-autobot, rojacob, simaishi, stcannon, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in hickory-proto. A remote attacker can trigger a Denial of Service (DoS) by sending crafted Domain Name System (DNS) messages or spoofed responses with excessively large record counts. The parser preallocates memory based on untrusted message header values before reading any record data, causing significant memory consumption that can exhaust system resources.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-11-08 02:06:29 UTC
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.