CVE-2026-47184

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 6.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.0%, top 93% 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: cna:github_m, epss
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.

zeroconf has unbounded DNS record cache that allows LAN-local memory exhaustion via multicast flood

Impact

DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache with no cap on entry count. The only pre-existing protection was a PTR TTL floor (_DNS_PTR_MIN_TTL = 1125 s, RFC 6762 §10), which actually *prolonged* attacker-injected records, and a periodic async_expire on _CACHE_CLEANUP_INTERVAL = 10 s that could not keep up with a flood.

Any unauthenticated host on the local link (UDP/5353, 224.0.0.251 / ff02::fb) can multicast valid mDNS responses with unique names (RFC 6762 §11 allows up to 253 bytes each) and watch them accumulate. On memory-constrained deployments (Home Assistant on Raspberry-Pi-class hardware is the canonical victim) sustained traffic OOM-kills the process; under lighter load, every cache lookup and every periodic expiry pass grows linearly slower, starving asyncio and breaking unrelated zeroconf consumers (discovery, registration, ServiceBrowser callbacks). A second variant — re-multicasting cached records with shifting TTLs — grows _expire_heap unbounded between cleanup runs without touching cache or _total_records.

Patches

Fixed in zeroconf 0.149.6 (PR #1718). Upgrade to >= 0.149.6.

Workarounds

There is no in-process workaround; upgrading is the fix. Otherwise, restrict mDNS (UDP/5353) to trusted Layer-2 segments via AP client isolation, guest-network separation, or host firewall rules.

Resources

CVSS v3
6.5
EG Score
6.5(low)
EPSS
6.7%
KEV
Not listed

Published

May 29, 2026

Last Modified

May 29, 2026

Vendor 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

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
zeroconf0.100.0 ... 0.99.0 (253 versions)0.149.7—

Data Freshness Timeline

(refreshed 3× in last 7d / 15× 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.

  1. 2026-07-16 01:48 UTCEG score recompute
  2. 2026-07-14 13:53 UTCEG score recompute
  3. 2026-07-11 17:22 UTCEG score recompute
  4. 2026-07-08 17:15 UTCEG score recompute
  5. 2026-07-02 03:46 UTCEG score recompute
  6. 2026-07-01 01:17 UTCEG score recompute
  7. 2026-06-29 14:09 UTCEG score recompute
  8. 2026-06-28 16:16 UTCEG score recompute
  9. 2026-06-27 18:23 UTCEG score recompute
  10. 2026-06-26 20:29 UTCEG score recompute
  11. 2026-06-25 22:36 UTCEG score recompute
  12. 2026-06-25 00:41 UTCEG score recompute
  13. 2026-06-24 02:47 UTCEG score recompute
  14. 2026-06-18 22:21 UTCEG score recompute
  15. 2026-06-17 13:01 UTCEG score recompute
  16. 2026-06-16 15:06 UTCEG score recompute
  17. 2026-06-15 14:54 UTCEG score recompute
  18. 2026-06-14 23:18 UTCEPSS rescore
  19. 2026-06-14 17:00 UTCEG score recompute
  20. 2026-06-13 23:00 UTCEPSS rescore
  21. 2026-06-13 19:06 UTCEG score recompute
  22. 2026-06-12 23:12 UTCEPSS rescore
  23. 2026-06-12 21:12 UTCEG score recompute
  24. 2026-06-11 23:18 UTCEG score recompute
  25. 2026-06-11 01:25 UTCEG score recompute
Show 12 more
  1. 2026-06-10 03:32 UTCEG score recompute
  2. 2026-06-09 05:38 UTCEG score recompute
  3. 2026-06-08 07:45 UTCEG score recompute
  4. 2026-06-07 09:52 UTCEG score recompute
  5. 2026-06-06 11:58 UTCEG score recompute
  6. 2026-06-05 14:06 UTCEG score recompute
  7. 2026-06-04 16:13 UTCEG score recompute
  8. 2026-06-03 18:20 UTCEG score recompute
  9. 2026-06-02 20:27 UTCEG score recompute
  10. 2026-06-01 22:34 UTCEG score recompute
  11. 2026-06-01 00:41 UTCEG score recompute
  12. 2026-05-29 20:20 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-47184?
CVE-2026-47184 is a medium vulnerability published on May 29, 2026. zeroconf has unbounded DNS record cache that allows LAN-local memory exhaustion via multicast flood Impact DNSCache.asyncadd inserted every response record into cache, expirations, expireheap, and servicecache with no cap on entry count. The only pre-existing protection was a PTR TTL floor…
When was CVE-2026-47184 disclosed?
CVE-2026-47184 was first published in the National Vulnerability Database on May 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47184 actively exploited?
CVE-2026-47184 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-47184?
CVE-2026-47184 has a CVSS v4.0 base score of 6.5 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-47184?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47184, 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-2026-47184

Explore →

Is Your Infrastructure Affected by CVE-2026-47184?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs