Bug 2501852 (CVE-2026-48045)

Summary:	CVE-2026-48045 zeroconf: Zeroconf: Unauthenticated network attacker can cause Denial of Service
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	eglynn, jjoyce, jpretori, jschluet, lhh, mburns, mgarciac
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in zeroconf, a Python library for network service discovery. This vulnerability allows an unauthenticated attacker on the local network to send specially crafted queries. These queries can cause the system to retain large amounts of data and trigger excessive processing, leading to a denial of service (DoS) due to memory exhaustion and high CPU usage.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2508072
Bug Blocks:

Description OSIDB Bzimport 2026-07-17 19:02:28 UTC

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.