CVSS 3.1
6.5 mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-47180
Medium (6.5) in paulsm zeroconf. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in zeroconf 0.149.5.
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.5, DNSIncoming._decode_labels_at_offset recurses once per DNS-name compression pointer, and a single mDNS packet carrying chained pointers can trigger a RecursionError that escapes DNSIncoming.__init__, causing sustained CPU burn, log flooding, and degraded mDNS-dependent features for unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb). This issue is fixed in version 0.149.5.
Severity
- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 30% of CVEs (scores of 2026-10-31)
- CWE
- CWE-674
- Published
- Modified
- Record from
- the NVD, synced
Affected
- paulsm:zeroconf
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-9pgc-3ccv-5297 | PyPI | zeroconf | <0.149.5 | 0.149.5 |
| PYSEC-2026-3436 | PyPI | zeroconf | <0.149.5 | 0.149.5 |
References
- https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cf
- https://github.com/python-zeroconf/python-zeroconf/pull/1719
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297