Vulnerability 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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Paulsm | Zeroconf | < 0.149.5 |
Related Weaknesses (CWE)
References
- https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef71Patch
- https://github.com/python-zeroconf/python-zeroconf/pull/1719Issue TrackingPatch
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5Release Notes
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgcVendor AdvisoryPatch
FAQ
What is CVE-2026-47180?
CVE-2026-47180 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 pa...
How severe is CVE-2026-47180?
CVE-2026-47180 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-47180?
Check the references section above for vendor advisories and patch information. Affected products include: Paulsm Zeroconf.