Bug 2480125 (CVE-2026-41292)

Summary: CVE-2026-41292 unbound: Unbound: Denial of Service via excessive EDNS options
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: anujha, asoldano, bbaranow, bmaxwell, bstansbe, dlofthou, eglynn, istudens, ivassile, iweiss, jjoyce, jmitchel, jpretori, jschluet, kshier, lhh, mburns, mgarciac, mosmerov, msvehla, nwallace, pesilva, pjindal, pmackay, rhel-process-autobot, rstancel, teagle, thjenkin, vdosoudi, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Unbound. A remote attacker can exploit this vulnerability by sending queries with an excessive number of EDNS (Extension Mechanisms for DNS) options. This can cause Unbound threads to be held hostage while parsing and creating internal data structures for these options. Coordinated attacks can lead to resource exhaustion, resulting in a degradation of service or a denial of service (DoS) for legitimate users.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2491930, 2491933, 2491935, 2491936, 2491940, 2491941, 2491943, 2491931, 2491932, 2491934, 2491937, 2491939, 2491942    
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Description OSIDB Bzimport 2026-05-20 10:01:17 UTC 
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).
Comment 3 errata-xmlrpc 2026-07-07 16:03:40 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:36320 https://access.redhat.com/errata/RHSA-2026:36320
Comment 4 errata-xmlrpc 2026-07-08 16:10:17 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:36777 https://access.redhat.com/errata/RHSA-2026:36777
Comment 5 errata-xmlrpc 2026-07-09 12:48:19 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:37282 https://access.redhat.com/errata/RHSA-2026:37282