Bug 2481349

Summary: CVE-2026-5947 dhcp: SIG(0) validation during query flood may lead to undefined behavior [fedora-all]
Product: [Fedora] Fedora Reporter: Sandipan Roy <saroy>
Component: dhcpAssignee: Martin Osvald 🛹 <mosvald>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: fhrdina, jorton, mosvald, pavel, pemensik
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["1722d21e-e8ce-4a9a-86bb-1bffe025fd30"]}
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Last Closed: 2026-05-28 05:49:13 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2479772    

Description Sandipan Roy 2026-05-26 03:46:50 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Comment 1 Martin Osvald 🛹 2026-05-28 05:49:13 UTC 
ISC DHCP is not affected. It doesn't perform SIG(0) validation or process any DNS messages that can lead to this. This is a BIND server-side issue.

ISC DHCP uses portions of the ISC BIND libraries (primarily libdns, omapi, and libisccfg) only to support DDNS (TSIG support, DNS message construction/parsing, DHCID generation), OMAPI related operations, basic functions (configuration handling, data structures, logging, networking primitives).