CVE-2026-47180 Zeroconf: Unbounded recursion in DNS compression-pointer decoder allows LAN-local denial of service

Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.5, DNSIncoming.decodelabelsatoffset recurses once per DNS-name compression pointer, and a single mDNS packet carrying chained pointers can trigger a RecursionError that escapes DNSIncoming.init, causing...

PYSEC-2026-3439 zeroconf has unbounded DNS record cache that allows LAN-local memory exhaustion via multicast flood

Impact DNSCache.asyncadd inserted every response record into cache, expirations, expireheap, and servicecache with no cap on entry count. The only pre-existing protection was a PTR TTL floor DNSPTRMINTTL = 1125 s, RFC 6762 §10, which actually prolonged attacker-injected records, and a periodic...