{"id":"CVE-2026-47184","aliases":["GHSA-rfg2-pjw2-56x2","PYSEC-2026-3439"],"url":"https://o3.security/vulnerability/CVE-2026-47184","summary":"Zeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood","details":"Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.","published":"2026-07-17T18:25:07.387Z","modified":"2026-08-19T03:48:18.126534861Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00238,"percentile":0.15069,"asOf":"2026-08-20"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"zeroconf","fixedVersion":"0.149.7"}],"fix":{"url":"https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4","label":"python-zeroconf/python-zeroconf@0ad3f37"},"references":[{"type":"WEB","url":"https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47184.json"},{"type":"ADVISORY","url":"https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47184"},{"type":"REPORT","url":"https://github.com/python-zeroconf/python-zeroconf/issues/1715"},{"type":"FIX","url":"https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4"},{"type":"FIX","url":"https://github.com/python-zeroconf/python-zeroconf/pull/1718"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-19T03:48:18.126534861Z"}}