CVE-2026-47180

EUVD-2026-45247
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
ADJACENT_NETWORK
LOW
NONE
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 29.93%
Affected Products (NVD)
VendorProductVersion
paulsmzeroconf
𝑥
< 0.149.5
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
python-zeroconf
bookworm
vulnerable
bullseye
vulnerable
forky
0.150.0-1
fixed
sid
0.150.0-1
fixed
trixie
vulnerable
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
python-zeroconf
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
resolute
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf
https://github.com/python-zeroconf/python-zeroconf/pull/1719
https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5
https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297