CVE-2026-48487

MEDIUM

python-zeroconf < 0.149.16 - LAN-Local mDNS RDLENGTH Cache Corruption

Title source: manual

Description

Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.16, _read_character_string and _read_string in src/zeroconf/_protocol/incoming.py advanced self.offset by attacker-declared RDLENGTH without checking it against self._data_len, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to send a TXT, HINFO, or A/AAAA record with rdlength=65535 and seed DNSCache and ServiceInfo.properties with truncated, attacker-shaped key/value or address records. This issue is fixed in version 0.149.16.

References (5)

Core 5

Core References

X_Refsource_Misc x_refsource_misc

https://github.com/python-zeroconf/python-zeroconf/issues/1752

X_Refsource_Misc x_refsource_misc

https://github.com/python-zeroconf/python-zeroconf/pull/1756

X_Refsource_Confirm x_refsource_confirm

https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-qc2x-6f54-m6h9

X_Refsource_Misc x_refsource_misc

https://github.com/python-zeroconf/python-zeroconf/commit/544449596e645fcaad3834fa0cb614a54f847a82

View Writeup ZIP pw:eip

X_Refsource_Misc x_refsource_misc

https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.16

Scores

CVSS v4 5.3

EPSS 0.0020

EPSS Percentile 10.5%

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-130

Status published

Products (1)

python-zeroconf/python-zeroconf < 0.149.16

Published Jul 17, 2026

Tracked Since Jul 18, 2026