CVE-2026-47184
MEDIUMZeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood
Title source: cnaDescription
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.
References (5)
Core 5
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2
X_Refsource_Misc x_refsource_misc
https://github.com/python-zeroconf/python-zeroconf/issues/1715
X_Refsource_Misc x_refsource_misc
https://github.com/python-zeroconf/python-zeroconf/pull/1718
X_Refsource_Misc x_refsource_misc
https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4
X_Refsource_Misc x_refsource_misc
https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7
Scores
CVSS v3
6.5
EPSS
0.0024
EPSS Percentile
15.4%
Attack Vector
ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-770
Status
published
Products (1)
python-zeroconf/python-zeroconf
< 0.149.7
Published
Jul 17, 2026
Tracked Since
Jul 18, 2026