{"id":"CVE-2026-47183","aliases":["GHSA-phvx-9mgw-67r5","PYSEC-2026-3437"],"url":"https://o3.security/vulnerability/CVE-2026-47183","summary":"Zeroconf: Unbounded exception-dedup state retains packet buffers via traceback frame locals, enabling LAN-local memory exhaustion","details":"Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.6, DNSIncoming._log_exception_debug and the four QuietLogger exception-dedup methods stored an unbounded _seen_logs dictionary keyed by attacker-influenced IncomingDecodeError messages, retaining sys.exc_info() tracebacks whose frame locals kept raw packet self.data buffers and allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to drive memory growth until mDNS-dependent features degrade or the process is OOM-killed. This issue is fixed in version 0.149.6.","published":"2026-07-17T18:22:59.803Z","modified":"2026-08-19T03:48:17.625148904Z","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":0.15068,"asOf":"2026-08-20"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"zeroconf","fixedVersion":"0.149.6"}],"fix":{"url":"https://github.com/python-zeroconf/python-zeroconf/commit/95561e28b24922358f1991e38e3a86d70d72dcec","label":"python-zeroconf/python-zeroconf@95561e2"},"references":[{"type":"WEB","url":"https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47183.json"},{"type":"ADVISORY","url":"https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-phvx-9mgw-67r5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47183"},{"type":"REPORT","url":"https://github.com/python-zeroconf/python-zeroconf/issues/1714"},{"type":"FIX","url":"https://github.com/python-zeroconf/python-zeroconf/commit/95561e28b24922358f1991e38e3a86d70d72dcec"},{"type":"FIX","url":"https://github.com/python-zeroconf/python-zeroconf/pull/1717"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-19T03:48:17.625148904Z"}}