Zeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood
Summary
| CVE | CVE-2026-47184 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-17 19:17:15 UTC |
| Updated | 2026-07-21 03:16:41 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from [email protected]
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.002410000 probability, percentile 0.153320000 (date 2026-07-21)
Problem Types: CWE-770 | CWE-770 CWE-770: Allocation of Resources Without Limits or Throttling
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | DECLARED | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Python-zeroconf | Python-zeroconf | affected < 0.149.7 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7 | [email protected] | github.com | |
| github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d32... | [email protected] | github.com | |
| github.com/python-zeroconf/python-zeroconf/issues/1715 | [email protected] | github.com | |
| github.com/python-zeroconf/python-zeroconf/pull/1718 | [email protected] | github.com | |
| github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.