CVSS 3.1
6.5 mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-48045
Medium (6.5) in paulsm zeroconf. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in zeroconf 0.149.12.
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.
Severity
- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 30% of CVEs (scores of 2026-10-31)
- CWE
- CWE-770
- Published
- Modified
- Record from
- the NVD, synced
Affected
- paulsm:zeroconf
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-9663-mqmp-p9mm | PyPI | zeroconf | <0.149.12 | 0.149.12 |
| PYSEC-2026-3435 | PyPI | zeroconf | <0.149.12 | 0.149.12 |
References
- https://github.com/python-zeroconf/python-zeroconf/commit/b22c8ff19c66c68907d220a4823c0950f4fa93f7
- https://github.com/python-zeroconf/python-zeroconf/pull/1751
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.12
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9663-mqmp-p9mm