Bug 2537323

Summary: CVE-2026-80225 unbound: Unbound: Denial of Service via continuous queries on TCP/DoT connection [fedora-all]
Product: [Fedora] Fedora Reporter: Srikanth Balasubramanian <sbalasub>
Component: unboundAssignee: Paul Wouters <paul.wouters>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: dns-sig, minfrin, paul.wouters, pemensik, pj.pandit, tkorbar
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["b670c573-928c-498d-b5e4-eeee054d3425"]}
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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: 2535055    

Description Srikanth Balasubramanian 2026-09-21 08:27:18 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.

In NLnetLabs Unbound up to and including 1.26.0, a degradation of service vulnerability is present in the TCP/DoT reading procedure where there is no limit on consecutive reads. A malicious actor that can stream and sustain a rate of distinct uncached names over the TCP/DoT connection, monopolizes a single worker's entire event loop for as long as its writes stay ahead of the drain.