Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.12, AsyncListener.handle_query_or_defer retained every truncated TC-bit incoming query, each up to _MAX_MSG_ABSOLUTE = 8966 bytes, in self._deferred[addr] and armed a per-address timer in self._timers[addr] without capping the per-address list or distinct addr keys, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to spoof sources, grow _deferred and _timers, and cause memory exhaustion and quadratic CPU burn. This issue is fixed in version 0.149.12.
Metrics
Affected Vendors & Products
References
History
Wed, 29 Jul 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
Thu, 23 Jul 2026 21:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Python-zeroconf
Python-zeroconf python-zeroconf |
|
| Vendors & Products |
Python-zeroconf
Python-zeroconf python-zeroconf |
Fri, 17 Jul 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
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 0.149.12, AsyncListener.handle_query_or_defer retained every truncated TC-bit incoming query, each up to _MAX_MSG_ABSOLUTE = 8966 bytes, in self._deferred[addr] and armed a per-address timer in self._timers[addr] without capping the per-address list or distinct addr keys, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to spoof sources, grow _deferred and _timers, and cause memory exhaustion and quadratic CPU burn. This issue is fixed in version 0.149.12. | |
| Title | Zeroconf: Unbounded TC-deferred queue allows LAN-local memory exhaustion via spoofed-source flood | |
| Weaknesses | CWE-770 | |
| References |
|
|
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-07-17T18:26:19.274Z
Updated: 2026-07-17T19:21:38.396Z
Reserved: 2026-05-20T18:15:53.578Z
Link: CVE-2026-48045
Updated: 2026-07-17T19:21:34.875Z
No data.