Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M
CVE-2026-47183Zeroconf: Unbounded exception-dedup state retains packet buffers via traceback frame locals, enabling LAN-local memory exhaustion
Medium 6.5
In plain English
A medium-severity uncontrolled resource consumption in python-zeroconf from python-zeroconf. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.6, DNSIncoming._log_exception_debug and the four QuietLogger exception-dedup methods stored an unbounded _seen_logs dictionary keyed by attacker-influenced IncomingDecodeError messages, retaining sys.exc_info() tracebacks whose frame locals kept raw packet self.data buffers and allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to drive memory growth until mDNS-dependent features degrade or the process is OOM-killed. This issue is fixed in version 0.149.6.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | python-zeroconf | no fix listed | DEBIAN-CVE-2026-47183 |
| Debian:13 | python-zeroconf | no fix listed | DEBIAN-CVE-2026-47183 |
| Debian:14 | python-zeroconf | 0.149.6-1 | DEBIAN-CVE-2026-47183 |
| PyPI | zeroconf | 0.149.6 | GHSA-phvx-9mgw-67r5 |
| PyPI | zeroconf | 0.149.6 | PYSEC-2026-3437 |
| Ubuntu:22.04:LTS | python-zeroconf | no fix listed | UBUNTU-CVE-2026-47183 |
| Ubuntu:24.04:LTS | python-zeroconf | no fix listed | UBUNTU-CVE-2026-47183 |
| Ubuntu:26.04:LTS | python-zeroconf | no fix listed | UBUNTU-CVE-2026-47183 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-zeroconf | python-zeroconf | < 0.149.6 |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-phvx-9mgw-67r5 x_refsource_CONFIRM
- https://github.com/python-zeroconf/python-zeroconf/issues/1714 x_refsource_MISC
- https://github.com/python-zeroconf/python-zeroconf/pull/1717 x_refsource_MISC
- https://github.com/python-zeroconf/python-zeroconf/commit/95561e28b24922358f1991e38e3a86d70d72dcec x_refsource_MISC
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.6 x_refsource_MISC