CVE-2026-47180
Zeroconf is a pure Python implementation of multicast DNS service discovery.
Does this matter?
Lower severity and a low EPSS score (0.37%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.37% probability · 30th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-674
- Affected
- paulsm/zeroconf
- Source
- security-advisories@github.com
References
- https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cfPatch
- https://github.com/python-zeroconf/python-zeroconf/pull/1719Issue Tracking, Patch
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5Release Notes
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297Vendor Advisory, Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.