DNSIncoming._log_exception_debug and the four QuietLogger exception-dedup methods stored an unbounded _seen_logs dict keyed by str(sys.exc_info()[1]). The seven IncomingDecodeError messages raised from _read_name / _decode_labels_at_offset (RFC 6762 §18 name-decoding error paths) all embed self.source — the peer's ephemeral source port, varying per packet — plus byte offset and pointer link, so every attacker-influenced combination produced a fresh dedup key. The stored value was the full sys.exc_info() triple, whose traceback's frame locals retained self.data (the raw inbound packet, up to 8966 bytes per RFC 6762 §17). Each unique malformed packet therefore pinned ~9 KB until process exit.
Any unauthenticated host on the local link (UDP/5353, 224.0.0.251 / ff02::fb) can drive memory growth at line rate; that includes a guest on the same Wi-Fi, a compromised IoT device, or a container on a shared bridge. On memory-constrained deployments (Home Assistant on Raspberry-Pi-class hardware is the canonical victim) sustained traffic trivially OOM-kills the process, and mDNS-dependent features (HomeKit, Chromecast/Matter, AirPlay, printers) degrade or fail.
Fixed in zeroconf 0.149.6 (PR #1717). Upgrade to >= 0.149.6.
There is no in-process workaround; upgrading is the fix. Otherwise, restrict mDNS (UDP/5353) to trusted Layer-2 segments via AP client isolation, guest-network separation, or host firewall rules.
No EPSS score in this advisory JSON.
| Base score | Version | Severity | Vector |
|---|---|---|---|
| 6.5 | 3.1 | — |
|
| Type | Value |
|---|---|
| GHSA | GHSA-phvx-9mgw-67r5 ↗ |
| CVE | CVE-2026-47183 ↗ |
| CWE id | Name |
|---|---|
| CWE-400 | Uncontrolled Resource Consumption |
Vulnerable version ranges and first patched releases as published by GitHub.
| Ecosystem | Package | Vulnerable range | First patched | Vulnerable functions |
|---|---|---|---|---|
| pip | zeroconf | < 0.149.6 | 0.149.6 | — |