CVSS 4.0
5.3 mediumCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NCVE-2026-48487
Medium (5.3) in paulsm zeroconf. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in zeroconf 0.149.16.
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.
Severity
CVSS 3.1
5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N- EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-31)
- CWE
- CWE-130
- Published
- Modified
- Record from
- the NVD, synced
Affected
- paulsm:zeroconf
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-qc2x-6f54-m6h9 | PyPI | zeroconf | <0.149.16 | 0.149.16 |
| PYSEC-2026-3438 | PyPI | zeroconf | <0.149.16 | 0.149.16 |
References
- https://github.com/python-zeroconf/python-zeroconf/commit/544449596e645fcaad3834fa0cb614a54f847a82
- https://github.com/python-zeroconf/python-zeroconf/issues/1752
- https://github.com/python-zeroconf/python-zeroconf/pull/1756
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.16
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-qc2x-6f54-m6h9