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.
CVE-2026-47180
MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 86% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.5
- EG Score
- 6.5(medium)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity65% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 13.9%
- KEV
- Not listed
Published
May 29, 2026
Last Modified
July 17, 2026
Advisory Details (4)
Auto-updated Jul 17, 2026Patch available. Sources: github_commit, github_release, github, github_pr.
github_release Patch Available
0.149.5
Patch available: python-zeroconf/python-zeroconf 0.149.5
https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.5github_commit Patch Available
commit f9e23592137f (python-zeroconf/python-zeroconf)
Patch available: python-zeroconf/python-zeroconf 0.149.5 (contains commit f9e23592137f)
https://github.com/python-zeroconf/python-zeroconf/commit/f9e23592137f30fdf7ef710dba065da31c79b1cfgithub_pr Patch Available
fix: bound DNS compression-pointer chain depth in DNSIncoming
Patch available: python-zeroconf/python-zeroconf 0.149.5 (PR #1719 merged 2026-05-18)
https://github.com/python-zeroconf/python-zeroconf/pull/1719github Patch Available
Unbounded recursion in DNS compression-pointer decoder allows LAN-local denial of service · Advisory · python-zeroconf/python-zeroconf · GitHub
https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-9pgc-3ccv-5297Vendor Advisories for CVE-2026-47180(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| zeroconf | 0.100.0 ... 0.99.0 (251 versions) | 0.149.5 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 03:17 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-06-14 23:18 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-05-29 20:20 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-47180?
CVE-2026-47180 is a medium vulnerability published on May 29, 2026. Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.5, DNSIncoming.decodelabelsatoffset recurses once per DNS-name compression pointer, and a single mDNS packet carrying chained pointers can trigger a RecursionError that escapes DNSIncoming.init, causing…
When was CVE-2026-47180 disclosed?
CVE-2026-47180 was first published in the National Vulnerability Database on May 29, 2026, with the most recent update on July 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47180 actively exploited?
CVE-2026-47180 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-47180?
CVE-2026-47180 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-47180?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47180, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-47180
Is Your Infrastructure Affected by CVE-2026-47180?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.