{"id":"CVE-2026-47180","state":"PUBLISHED","title":"Zeroconf: Unbounded recursion in DNS compression-pointer decoder allows LAN-local denial of service","description":"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.","publishedAt":"2026-07-17T18:21:25.199Z","updatedAt":"2026-07-17T19:21:29.700Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["python-zeroconf python-zeroconf"],"affected":[{"vendor":"python-zeroconf","product":"python-zeroconf","versions":[{"version":"< 0.149.5","status":"affected"}]}],"references":["https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297","https://github.com/python-zeroconf/python-zeroconf/pull/1719","https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf","https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5"],"weaknesses":["CWE-674"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/47xxx/CVE-2026-47180.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-47180","state":"PUBLISHED","datePublished":"2026-07-17T18:21:25.199Z","dateUpdated":"2026-07-17T19:21:29.700Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-18T22:07:37.434Z"},"containers":{"cna":{"title":"Zeroconf: Unbounded recursion in DNS compression-pointer decoder allows LAN-local denial of service","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"python-zeroconf","product":"python-zeroconf","versions":[{"version":"< 0.149.5","status":"affected"}]}],"references":[{"url":"https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297","name":"https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/python-zeroconf/python-zeroconf/pull/1719","name":"https://github.com/python-zeroconf/python-zeroconf/pull/1719","tags":["x_refsource_MISC"]},{"url":"https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf","name":"https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf","tags":["x_refsource_MISC"]},{"url":"https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5","name":"https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"ADJACENT_NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-674","lang":"en","description":"CWE-674: Uncontrolled Recursion","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-17T18:21:25.199Z"},"source":{"advisory":"GHSA-9pgc-3ccv-5297","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-17T19:21:22.892470Z","id":"CVE-2026-47180","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-17T19:21:29.700Z"}}]}}}