CVE-2026-47184

medium

Description

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

https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2

https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7

https://github.com/python-zeroconf/python-zeroconf/pull/1718

https://github.com/python-zeroconf/python-zeroconf/issues/1715

https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4

Details

Source: Mitre, NVD

Published: 2026-07-17

Updated: 2026-07-23

Risk Information

CVSS v2

Base Score: 6.1

Vector: CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00023