CVE-2026-47183

Process crash via unbounded exception-dedup state

Published Jul 17, 2026 · Updated Jul 17, 2026

Memory exhaustion in python-zeroconf before 0.149.6 allows remote attackers to crash consuming processes via malformed mDNS packets. The DNSIncoming._log_exception_debug and QuietLogger deduplication methods key an unbounded _seen_logs dictionary with attacker-controlled decode-error text and retain full traceback tuples that keep raw packet buffers alive. Access to the same local link and sustained malformed UDP/5353 traffic are required; memory growth degrades mDNS-dependent features and can end in an out-of-memory process kill.

CVSS severity6.5
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory exhaustion in python-zeroconf before 0.149.6 allows remote attackers to crash consuming processes via malformed mDNS packets. The DNSIncoming._log_exception_debug and QuietLogger deduplication methods key an unbounded _seen_logs dictionary with attacker-controlled decode-error text and retain full traceback tuples that keep raw packet buffers alive. Access to the same local link and sustained malformed UDP/5353 traffic are required; memory growth degrades mDNS-dependent features and can end in an out-of-memory process kill.

The record

CVE
CVE-2026-47183
Published
Jul 17, 2026
Updated
Jul 17, 2026
Vendor
python-zeroconf
Product
python-zeroconf
Classifications
CWE-400, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.149.6

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

python-zeroconf · python-zeroconfversion=< 0.149.6

Published CVSS scores

6.5GitHubCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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