CVE-2026-47183

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

MEDIUM
6.5
CVSS Score
Published: July 17, 2026 at 06:22 PM UTC
Updated: August 17, 2026 at 08:05 PM UTC
2 products affected across 2 vendorsZeroconfZeroconf

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.149.6
Affected range stops below 0.149.6, so it looks safe — our inference, not a vendor statement
v < 0.149.6
Affected range stops below 0.149.6, so it looks safe — our inference, not a vendor statement

References (5)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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