CVE-2026-47183

MEDIUM 6.5

Zeroconf: Unbounded exception-dedup state retains packet buffers via traceback frame locals, enabling LAN-local memory exhaustion

CVSS Score

6.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-400
Vendor	python-zeroconf
Product	python-zeroconf
Published	Jul 17, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

python-zeroconf / python-zeroconf

< 0.149.6

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-phvx-9mgw-67r5 github.com: https://github.com/python-zeroconf/python-zeroconf/issues/1714 github.com: https://github.com/python-zeroconf/python-zeroconf/pull/1717 github.com: https://github.com/python-zeroconf/python-zeroconf/commit/95561e28b24922358f1991e38e3a86d70d72dcec github.com: https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.6