CVE-2019-16789

HIGHNVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under NVD CVSS v3. EPSS exploit probability: 0.9%, top 24% 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
7.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 3%CVSS: 7.1Exploit: NoneExposed: 0

A fix is available — apply it.

In Waitress through version 1.4.0, if a proxy server is used in front of waitress, an invalid request may be sent by an attacker that bypasses the front-end and is parsed differently by waitress leading to a potential for HTTP request smuggling. Specially crafted requests containing special whitespace characters in the Transfer-Encoding header would get parsed by Waitress as being a chunked request, but a front-end server would use the Content-Length instead as the Transfer-Encoding header is considered invalid due to containing invalid characters. If a front-end server does HTTP pipelining to a backend Waitress server this could lead to HTTP request splitting which may lead to potential cache poisoning or unexpected information disclosure. This issue is fixed in Waitress 1.4.1 through more strict HTTP field validation.

CVSS v3
7.1
EG Score
7.1(medium)
EPSS
83.4%
KEV
Not listed

Published

December 26, 2019

Last Modified

November 21, 2024

References (16)

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatquay/quay-rhel8:v3.4.0-512021-02-04redhat
redhatpython-waitress-0:1.4.2-1.el8ost2020-03-05redhat

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)
PyPI(1)
PackageVulnerable rangeFixed inDependents
waitress0.1 ... 1.4.0 (38 versions)1.4.1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(2)

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 9× in last 7d / 37× 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. 2026-07-11 08:24 UTCEPSS rescore
  2. 2026-07-11 08:24 UTCEPSS rescore
  3. 2026-07-09 19:06 UTCEPSS rescore
  4. 2026-07-08 15:11 UTCEPSS rescore
  5. 2026-07-07 13:43 UTCEPSS rescore
  6. 2026-07-06 16:25 UTCEPSS rescore
  7. 2026-07-06 16:25 UTCEPSS rescore
  8. 2026-07-06 02:20 UTCEPSS rescore
  9. 2026-07-05 02:27 UTCEPSS rescore
  10. 2026-07-04 06:28 UTCEPSS rescore
  11. 2026-07-02 13:46 UTCOSV refresh
  12. 2026-07-01 15:03 UTCEPSS rescore
  13. 2026-07-01 15:03 UTCEPSS rescore
  14. 2026-06-30 23:20 UTCEPSS rescore
  15. 2026-06-29 14:03 UTCEPSS rescore
  16. 2026-06-28 04:54 UTCEPSS rescore
  17. 2026-06-28 04:54 UTCEPSS rescore
  18. 2026-06-27 03:06 UTCEPSS rescore
  19. 2026-06-25 13:47 UTCEPSS rescore
  20. 2026-06-25 13:47 UTCEPSS rescore
  21. 2026-06-24 14:03 UTCEPSS rescore
  22. 2026-06-24 14:03 UTCEPSS rescore
  23. 2026-06-21 14:54 UTCEPSS rescore
  24. 2026-06-21 14:54 UTCEPSS rescore
  25. 2026-06-21 01:57 UTCEPSS rescore
Show 45 more
  1. 2026-06-21 01:57 UTCEPSS rescore
  2. 2026-06-19 19:23 UTCEPSS rescore
  3. 2026-06-19 19:23 UTCEPSS rescore
  4. 2026-06-18 17:50 UTCEPSS rescore
  5. 2026-06-17 17:50 UTCEPSS rescore
  6. 2026-06-16 17:50 UTCEPSS rescore
  7. 2026-06-15 17:45 UTCEPSS rescore
  8. 2026-06-14 23:15 UTCEPSS rescore
  9. 2026-06-14 23:15 UTCEPSS rescore
  10. 2026-06-14 12:13 UTCOSV refresh
  11. 2026-06-13 22:58 UTCEPSS rescore
  12. 2026-06-12 23:09 UTCEPSS rescore
  13. 2026-06-11 13:58 UTCEPSS rescore
  14. 2026-06-10 22:16 UTCEPSS rescore
  15. 2026-06-10 13:19 UTCEPSS rescore
  16. 2026-06-08 14:15 UTCEPSS rescore
  17. 2026-06-07 15:23 UTCEPSS rescore
  18. 2026-06-07 15:23 UTCEPSS rescore
  19. 2026-06-06 13:45 UTCEPSS rescore
  20. 2026-06-06 13:45 UTCEPSS rescore
  21. 2026-06-05 22:45 UTCEPSS rescore
  22. 2026-06-05 22:45 UTCEPSS rescore
  23. 2026-06-05 06:08 UTCEPSS rescore
  24. 2026-06-05 06:08 UTCEPSS rescore
  25. 2026-06-04 13:10 UTCEPSS rescore
  26. 2026-06-04 13:10 UTCEPSS rescore
  27. 2026-06-02 20:11 UTCEPSS rescore
  28. 2026-06-02 20:11 UTCEPSS rescore
  29. 2026-06-01 13:50 UTCEPSS rescore
  30. 2026-06-01 13:50 UTCEPSS rescore
  31. 2026-05-31 22:29 UTCEPSS rescore
  32. 2026-05-31 22:29 UTCEPSS rescore
  33. 2026-05-31 00:14 UTCEPSS rescore
  34. 2026-05-31 00:14 UTCEPSS rescore
  35. 2026-05-29 13:42 UTCEPSS rescore
  36. 2026-05-28 13:43 UTCEPSS rescore
  37. 2026-05-27 13:38 UTCEPSS rescore
  38. 2026-05-27 09:54 UTCEG score recompute
  39. 2026-05-27 09:54 UTCVendor advisory
  40. 2026-05-26 13:42 UTCEPSS rescore
  41. 2026-05-26 13:42 UTCEPSS rescore
  42. 2026-05-26 07:17 UTCEPSS rescore
  43. 2026-05-26 07:17 UTCEPSS rescore
  44. 2026-05-26 07:17 UTCEPSS rescore
  45. 2026-05-24 22:56 UTCOSV refresh

Frequently asked(5)

What is CVE-2019-16789?
CVE-2019-16789 is a high vulnerability published on December 26, 2019. In Waitress through version 1.4.0, if a proxy server is used in front of waitress, an invalid request may be sent by an attacker that bypasses the front-end and is parsed differently by waitress leading to a potential for HTTP request smuggling. Specially crafted requests containing special…
When was CVE-2019-16789 disclosed?
CVE-2019-16789 was first published in the National Vulnerability Database on December 26, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2019-16789 actively exploited?
CVE-2019-16789 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 83.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2019-16789?
CVE-2019-16789 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2019-16789?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2019-16789, 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

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