Bug 2508072

Summary: CVE-2026-48045 python-zeroconf: Zeroconf: Unauthenticated network attacker can cause Denial of Service [fedora-all]
Product: [Fedora] Fedora Reporter: jkelly <jkelly>
Component: python-zeroconfAssignee: Miro Hrončok <mhroncok>
Status: CLOSED NEXTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: 45CC: mhroncok, pbrobinson, python-packagers-sig
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["82c54321-75f1-401d-99fc-1233a4355dfa"]}
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Last Closed: 2026-08-29 10:11:09 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: 2501852    

Description jkelly 2026-07-28 16:18:13 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.

Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.12, AsyncListener.handle_query_or_defer retained every truncated TC-bit incoming query, each up to _MAX_MSG_ABSOLUTE = 8966 bytes, in self._deferred[addr] and armed a per-address timer in self._timers[addr] without capping the per-address list or distinct addr keys, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to spoof sources, grow _deferred and _timers, and cause memory exhaustion and quadratic CPU burn. This issue is fixed in version 0.149.12.
Comment 1 Aoife Moloney 2026-08-17 15:39:37 UTC 
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.
Comment 2 Peter Robinson 2026-08-29 10:11:09 UTC 
Fixed in F-45+ because it's not possible to upgrade earlier releases without significant effort due to dependencies on newer protobuf releases not in older versions of Fedora.