medium6.5
CVE-2026-47184
zeroconf has unbounded DNS record cache that allows LAN-local memory exhaustion via multicast flood
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | zeroconf | < 0.149.7 | 0.149.7 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Paulsm | Zeroconf | before 0.149.7 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-rfg2-pjw2-56x2
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2
- https://github.com/python-zeroconf/python-zeroconf/issues/1715
- https://github.com/python-zeroconf/python-zeroconf/pull/1718
- https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7