CVE-2026-47180
Zeroconf: Unbounded recursion in DNS compression-pointer decoder allows LAN-local denial of service
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-674 |
| Vendor | python-zeroconf |
| Product | python-zeroconf |
| Published | Jul 17, 2026 |
| Last Updated | Jul 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
python-zeroconf / python-zeroconf
< 0.149.5
References
github.com: https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297 github.com: https://github.com/python-zeroconf/python-zeroconf/pull/1719 github.com: https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf github.com: https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5