CVE-2017-5637

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 73.7%, top 1% 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, nvd
Elevated
7.5
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 74%
CISA-KEV: Not listedEPSS: 74%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests. Apache ZooKeeper thru version 3.4.9 and 3.5.2 suffer from this issue, fixed in 3.4.10, 3.5.3, and later.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
99.4%
KEV
Not listed

Published

October 10, 2017

Last Modified

May 13, 2026

References (24)

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntupython-zookeeper (3.4.8-1ubuntu0.1~esm1) @ xenial2026-05-22ubuntu
redhatzookeeper2017-11-30redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
org.apache.zookeeper:zookeeper3.5.1-alpha, 3.5.2-alpha, 3.5.3-beta3.5.3—

All Vendor Advisories

(4)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 4× in last 7d / 21× 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. 2026-07-22 22:09 UTCEG score recompute
  2. 2026-07-22 14:04 UTCEPSS rescore
  3. 2026-07-22 14:04 UTCEPSS rescore
  4. 2026-07-20 17:04 UTCEPSS rescore
  5. 2026-07-15 16:54 UTCEPSS rescore
  6. 2026-07-15 01:56 UTCEPSS rescore
  7. 2026-07-15 01:56 UTCEPSS rescore
  8. 2026-07-12 05:43 UTCEPSS rescore
  9. 2026-07-11 16:52 UTCOSV refresh
  10. 2026-07-09 19:06 UTCEPSS rescore
  11. 2026-07-04 06:28 UTCEPSS rescore
  12. 2026-07-01 15:02 UTCEPSS rescore
  13. 2026-06-30 23:19 UTCEPSS rescore
  14. 2026-06-30 23:19 UTCEPSS rescore
  15. 2026-06-29 14:03 UTCEPSS rescore
  16. 2026-06-28 04:53 UTCEPSS rescore
  17. 2026-06-25 13:47 UTCEPSS rescore
  18. 2026-06-24 14:02 UTCEPSS rescore
  19. 2026-06-24 14:02 UTCEPSS rescore
  20. 2026-06-23 21:30 UTCEPSS rescore
  21. 2026-06-22 23:30 UTCOSV refresh
  22. 2026-06-21 14:54 UTCEPSS rescore
  23. 2026-06-21 14:54 UTCEPSS rescore
  24. 2026-06-18 17:50 UTCEPSS rescore
  25. 2026-06-17 17:50 UTCEPSS rescore
Show 45 more
  1. 2026-06-15 17:45 UTCEPSS rescore
  2. 2026-06-14 23:14 UTCEPSS rescore
  3. 2026-06-13 22:57 UTCEPSS rescore
  4. 2026-06-12 23:09 UTCEPSS rescore
  5. 2026-06-10 22:15 UTCEPSS rescore
  6. 2026-06-10 13:19 UTCEPSS rescore
  7. 2026-06-08 14:14 UTCEPSS rescore
  8. 2026-06-08 14:14 UTCEPSS rescore
  9. 2026-06-07 15:22 UTCEPSS rescore
  10. 2026-06-07 15:22 UTCEPSS rescore
  11. 2026-06-06 13:45 UTCEPSS rescore
  12. 2026-06-06 13:45 UTCEPSS rescore
  13. 2026-06-05 22:44 UTCEPSS rescore
  14. 2026-06-05 16:57 UTCOSV refresh
  15. 2026-06-05 06:08 UTCEPSS rescore
  16. 2026-06-05 06:08 UTCEPSS rescore
  17. 2026-06-04 13:10 UTCEPSS rescore
  18. 2026-06-02 20:11 UTCEPSS rescore
  19. 2026-06-02 20:11 UTCEPSS rescore
  20. 2026-06-01 13:49 UTCEPSS rescore
  21. 2026-05-31 22:28 UTCEPSS rescore
  22. 2026-05-31 22:28 UTCEPSS rescore
  23. 2026-05-31 00:14 UTCEPSS rescore
  24. 2026-05-31 00:14 UTCEPSS rescore
  25. 2026-05-29 13:41 UTCEPSS rescore
  26. 2026-05-28 13:42 UTCEPSS rescore
  27. 2026-05-28 13:42 UTCEPSS rescore
  28. 2026-05-27 13:38 UTCEPSS rescore
  29. 2026-05-27 13:38 UTCEPSS rescore
  30. 2026-05-26 13:42 UTCEPSS rescore
  31. 2026-05-26 13:42 UTCEPSS rescore
  32. 2026-05-22 21:15 UTCEPSS rescore
  33. 2026-05-22 21:15 UTCEPSS rescore
  34. 2026-05-22 21:15 UTCEPSS rescore
  35. 2026-05-22 21:15 UTCEPSS rescore
  36. 2026-05-22 21:15 UTCEPSS rescore
  37. 2026-05-22 09:10 UTCEG score recompute
  38. 2026-05-22 09:10 UTCVendor advisory
  39. 2026-05-21 22:40 UTCEPSS rescore
  40. 2026-05-20 22:37 UTCEPSS rescore
  41. 2026-05-20 22:37 UTCEPSS rescore
  42. 2026-05-20 22:37 UTCEPSS rescore
  43. 2026-05-20 11:21 UTCEPSS rescore
  44. 2026-05-20 11:21 UTCEPSS rescore
  45. 2026-05-18 21:30 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-42294
    First seen Jul 2, 2017

    Zookeeper 3.5.2 Client - Denial of Service

    Open source ↗

Related CVEs(same vendor)

Frequently asked(5)

What is CVE-2017-5637?
CVE-2017-5637 is a high vulnerability published on October 10, 2017. Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests. Apache ZooKeeper thru version 3.4.9 and 3.5.2 suffer from this issue, fixed in 3.4.10,…
When was CVE-2017-5637 disclosed?
CVE-2017-5637 was first published in the National Vulnerability Database on October 10, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2017-5637 actively exploited?
CVE-2017-5637 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2017-5637?
CVE-2017-5637 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2017-5637?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2017-5637, 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-2017-5637

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