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.
Metrics
Affected Vendors & Products
References
History
Wed, 29 Jul 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
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| Weaknesses | CWE-120 | |
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threat_severity
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cvssV3_1
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Thu, 23 Jul 2026 21:45:00 +0000
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Python-zeroconf
Python-zeroconf python-zeroconf |
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Python-zeroconf
Python-zeroconf python-zeroconf |
Mon, 20 Jul 2026 20:30:00 +0000
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ssvc
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Fri, 17 Jul 2026 18:45:00 +0000
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| Description | 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. | |
| Title | Zeroconf: Unvalidated rdlength in record payload readers allows LAN-local cache corruption via crafted mDNS packet | |
| Weaknesses | CWE-130 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-07-17T18:28:21.417Z
Updated: 2026-07-20T19:26:06.005Z
Reserved: 2026-05-21T15:33:08.291Z
Link: CVE-2026-48487
Updated: 2026-07-20T19:25:55.762Z
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