CVE-2026-48487: Paulsm Zeroconf

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.16, _read_character_string and _read_string in src/zeroconf/_protocol/incoming.py advanced self.offset by attacker-declared RDLENGTH without checking it against self._data_len, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to send a TXT, HINFO, or A/AAAA record with rdlength=65535 and seed DNSCache and ServiceInfo.properties with truncated, attacker-shaped key/value or address records. This issue is fixed in version 0.149.16.

Affected products

• Paulsm Zeroconf: before 0.149.16 (fixed in 0.149.16)

Published 2026-07-17. Last modified 2026-08-17.