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.
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| python-zeroconf | python-zeroconf | affected |
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No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
 Github GHSA |
GHSA-rfg2-pjw2-56x2 | zeroconf has unbounded DNS record cache that allows LAN-local memory exhaustion via multicast flood |
References
History
Fri, 17 Jul 2026 18:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Zeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood | |
| Weaknesses | CWE-770 | |
| References |
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| Metrics |
cvssV3_1
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Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-07-17T18:25:07.387Z
Reserved: 2026-05-18T22:07:37.434Z
Link: CVE-2026-47184
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
No data.
Weaknesses
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CWE-770
Allocation of Resources Without Limits or Throttling