CVE-2026-48045CWE-770denial-of-service

CVE-2026-48045

Medium · published July 17, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
29.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00370 · 29.7th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-07-17T23:17Z
Affected products (1)
ProductVersionsFixed in
paulsm/zeroconf< 0.149.120.149.12
References (4)
https://github.com/python-zeroconf/python-zeroconf/commit/b22c8ff19c66c68907d220a4823c0950f4fa93f7 · [email protected]https://github.com/python-zeroconf/python-zeroconf/pull/1751 · [email protected]https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.12 · [email protected]https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9663-mqmp-p9mm · [email protected]
EPSS history
Timeline
  • 17 JUL 18:26Z
    Zeroconf: Unbounded TC-deferred queue allows LAN-local memory exhaustion via spoofed-source flood
    cvelistv5