CVE-2026-48045

medium

Description

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.

References

https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9663-mqmp-p9mm

https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.12

https://github.com/python-zeroconf/python-zeroconf/pull/1751

https://github.com/python-zeroconf/python-zeroconf/commit/b22c8ff19c66c68907d220a4823c0950f4fa93f7

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: 0.00018