Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.
CVE-2026-47184
This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 68% 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).
- Lower severity and no public exploit yet
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 PROB
- 0%
- EPSS %ILE
- 32%
- KEV
- Not listed
Published
May 29, 2026
Last Modified
August 17, 2026
Advisory Details (5)
Auto-updated Jul 17, 2026Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood · Advisory · python-zeroconf/python-zeroconf · GitHub
https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x20.149.7
Patch available: python-zeroconf/python-zeroconf 0.149.7
https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7fix: bound DNSCache record count to prevent unbounded LAN-driven growth
Patch available: python-zeroconf/python-zeroconf 0.149.7 (PR #1718 merged 2026-05-18)
https://github.com/python-zeroconf/python-zeroconf/pull/1718Security: Unbounded DNS record cache can be filled by any LAN peer (memory exhaustion) · Issue #1715 · python-zeroconf/python-zeroconf · GitHub
https://github.com/python-zeroconf/python-zeroconf/issues/1715commit 0ad3f37b5b85 (python-zeroconf/python-zeroconf)
Patch available: python-zeroconf/python-zeroconf 0.149.7 (contains commit 0ad3f37b5b85)
https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4Vendor Advisories for CVE-2026-47184(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(5 across 5 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| python-zeroconf | 0.102.0-1 ... 0.97.0-1 (111 versions) | — | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| python-zeroconf | 0.102.0-1 ... 0.97.0-1 (79 versions) | — | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| python-zeroconf | 0.147.0-1 ... 0.150.0-1 (13 versions) | — | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| python-zeroconf | 0.147.0-1 ... 0.149.6-1 (9 versions) | 0.149.7-1 | — |
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| zeroconf | 0.100.0 ... 0.99.0 (253 versions) | 0.149.7 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 38× 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.
- 2026-09-04 05:06 UTCEPSS rescore
- 2026-09-02 14:12 UTCEPSS rescore
- 2026-09-01 13:54 UTCEPSS rescore
- 2026-08-30 19:17 UTCEPSS rescore
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-28 21:41 UTCEPSS rescore
- 2026-08-27 14:25 UTCEPSS rescore
- 2026-08-26 14:46 UTCEPSS rescore
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-25 04:15 UTCEG score recompute
- 2026-08-23 14:10 UTCEG score recompute
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 14:59 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 10:24 UTCEG score recompute
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 20:10 UTCEG score recompute
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 06:51 UTCEG score recompute
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 02:24 UTCEG score recompute
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 03:46 UTCEG score recompute
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- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 05:53 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 08:00 UTCEG score recompute
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-12 09:24 UTCEG score recompute
- 2026-08-11 08:14 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 10:21 UTCEG score recompute
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 12:27 UTCEG score recompute
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-07 16:41 UTCEG score recompute
- 2026-08-05 20:55 UTCEG score recompute
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 23:02 UTCEG score recompute
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:39 UTCEPSS rescore
- 2026-08-03 15:55 UTCEG score recompute
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-02 11:51 UTCEG score recompute
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 13:55 UTCEG score recompute
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-31 05:51 UTCEG score recompute
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-29 11:47 UTCEG score recompute
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-27 09:02 UTCEG score recompute
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 07:37 UTCEG score recompute
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 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
Frequently asked(5)
What is CVE-2026-47184?
When was CVE-2026-47184 disclosed?
Is CVE-2026-47184 actively exploited?
What is the CVSS score of CVE-2026-47184?
How do I remediate CVE-2026-47184?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-47184
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