CVE-2026-47180

Name	CVE-2026-47180
Description	Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.5, DNSIncoming._decode_labels_at_offset recurses once per DNS-name compression pointer, and a single mDNS packet carrying chained pointers can trigger a RecursionError that escapes DNSIncoming.__init__, causing sustained CPU burn, log flooding, and degraded mDNS-dependent features for unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb). This issue is fixed in version 0.149.5.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-zeroconf (PTS)	bullseye	0.26.1-1	vulnerable
	bookworm	0.47.3-1	vulnerable
	trixie	0.147.0-1	vulnerable
	forky, sid	0.150.0-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-zeroconf	source	(unstable)	0.149.6-1

Notes

https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297
https://github.com/python-zeroconf/python-zeroconf/pull/1719
Fixed by: https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf (0.149.5)