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BREW-AIRSHARE-CVE-2026-47183 (GHSA-PHVX-9MGW-67R5)

Vulnerability from osv_homebrew – Published: 2026-08-13 16:35 – Updated: 2026-09-17 19:58 – Source website
VLAI
Summary
zeroconf: Unbounded exception-dedup state retains packet buffers via traceback frame locals, enabling LAN-local memory exhaustion
Details

Impact

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.

Patches

Fixed in zeroconf 0.149.6 (PR #1717). Upgrade to >= 0.149.6.

Workarounds

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.

Resources

Severity
6.5 (Medium)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "zeroconf",
        "resource_purl": "pkg:pypi/zeroconf@0.150.0",
        "upstream_fixed_in": "0.149.6"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "airshare",
        "purl": "pkg:brew/airshare"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.1.5"
            },
            {
              "fixed": "0.1.6_23"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/zeroconf@0.150.0",
        "name": "zeroconf",
        "resource": "zeroconf",
        "strategy": "registry",
        "subject_version": "0.150.0"
      }
    ]
  },
  "details": "### Impact\n`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 \u00a718 name-decoding error paths) all embed `self.source` \u2014 the peer\u0027s ephemeral source port, varying per packet \u2014 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\u0027s frame locals retained `self.data` (the raw inbound packet, up to 8966 bytes per RFC 6762 \u00a717). Each unique malformed packet therefore pinned ~9 KB until process exit.\n\nAny 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.\n\n### Patches\nFixed in `zeroconf` 0.149.6 ([PR #1717](https://github.com/python-zeroconf/python-zeroconf/pull/1717)). Upgrade to `\u003e= 0.149.6`.\n\n### Workarounds\nThere 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.\n\n### Resources\n- [PR #1717](https://github.com/python-zeroconf/python-zeroconf/pull/1717), fix\n- [Issue #1714](https://github.com/python-zeroconf/python-zeroconf/issues/1714), public tracking issue\n- [RFC 6762 \u00a717](https://www.rfc-editor.org/rfc/rfc6762#section-17), [RFC 6762 \u00a718](https://www.rfc-editor.org/rfc/rfc6762#section-18), [CWE-400](https://cwe.mitre.org/data/definitions/400.html)",
  "id": "BREW-airshare-CVE-2026-47183",
  "modified": "2026-09-17T19:58:50Z",
  "published": "2026-08-13T16:35:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-phvx-9mgw-67r5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-zeroconf/python-zeroconf/issues/1714"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-zeroconf/python-zeroconf/pull/1717"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/python-zeroconf/python-zeroconf"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "zeroconf: Unbounded exception-dedup state retains packet buffers via traceback frame locals, enabling LAN-local memory exhaustion",
  "upstream": [
    "GHSA-phvx-9mgw-67r5",
    "CVE-2026-47183",
    "PYSEC-2026-3437"
  ]
}



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