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CVE PROGRAM SOURCE RECORD6.5 Medium

CVE-2026-47180

Zeroconf: Unbounded recursion in DNS compression-pointer decoder allows LAN-local denial of service

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

python-zeroconf python-zeroconf

  • < 0.149.5affected

References