CVE-2026-59898

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 84% 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
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, ab attacker can force WebSocket upgrade via the lax V07 (or V08) handshaker by sending Sec-WebSocket-Version: 7 and omitting Connection: Upgrade / Upgrade: websocket headers, completing a protocol switch that a proxy would not recognize as an Upgrade request and enabling HTTP request smuggling / protocol-confusion attacks. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: 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 computed
Severity75% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

July 22, 2026

Last Modified

August 6, 2026

Advisory Details (3)

Auto-updated Jul 29, 2026
Patch available. Sources: github, github_release.
github_release Patch Available

netty-4.2.16.Final

Patch available: netty/netty netty-4.2.16.Final

https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
github_release Patch Available

netty-4.1.136.Final

Patch available: netty/netty netty-4.1.136.Final

https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
github Patch Available

WebSockets V07/V08 handshaker missing Connection/Upgrade validation · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-4mp9-239f-g9hg

Vendor Advisories for CVE-2026-59898(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnetty-codec-http2026-07-30redhat

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (16 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (12 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (8 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (7 versions)——
Maven(1)
PackageVulnerable rangeFixed inDependents
io.netty:netty-codec-http4.0.0.Alpha1 ... 4.1.99.Final (229 versions)4.1.136.Final—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 86× 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.

Showing the most recent 100 of 158 total refreshes for this CVE.

  1. 2026-09-15 03:11 UTCEPSS rescore
  2. 2026-09-14 10:19 UTCVendor advisory
  3. 2026-09-13 22:25 UTCEG score recompute
  4. 2026-09-13 22:25 UTCVendor advisory
  5. 2026-09-13 16:47 UTCEPSS rescore
  6. 2026-09-13 09:02 UTCVendor advisory
  7. 2026-09-12 21:09 UTCEG score recompute
  8. 2026-09-12 21:09 UTCVendor advisory
  9. 2026-09-12 09:15 UTCVendor advisory
  10. 2026-09-11 21:03 UTCEG score recompute
  11. 2026-09-11 21:03 UTCVendor advisory
  12. 2026-09-11 14:53 UTCEPSS rescore
  13. 2026-09-11 09:09 UTCVendor advisory
  14. 2026-09-10 21:15 UTCEG score recompute
  15. 2026-09-10 21:15 UTCVendor advisory
  16. 2026-09-10 09:35 UTCEPSS rescore
  17. 2026-09-09 09:11 UTCEG score recompute
  18. 2026-09-09 09:11 UTCVendor advisory
  19. 2026-09-08 22:01 UTCEPSS rescore
  20. 2026-09-07 21:39 UTCEG score recompute
  21. 2026-09-07 21:39 UTCVendor advisory
  22. 2026-09-07 16:01 UTCEPSS rescore
  23. 2026-09-06 13:47 UTCEPSS rescore
  24. 2026-09-06 08:39 UTCVendor advisory
  25. 2026-09-05 19:33 UTCEG score recompute
Show 75 more
  1. 2026-09-05 19:33 UTCVendor advisory
  2. 2026-09-05 07:07 UTCEG score recompute
  3. 2026-09-05 07:07 UTCVendor advisory
  4. 2026-09-04 13:39 UTCEG score recompute
  5. 2026-09-04 13:39 UTCVendor advisory
  6. 2026-09-04 05:07 UTCEPSS rescore
  7. 2026-09-02 14:12 UTCEPSS rescore
  8. 2026-09-01 23:37 UTCEG score recompute
  9. 2026-09-01 23:37 UTCVendor advisory
  10. 2026-09-01 13:54 UTCEPSS rescore
  11. 2026-09-01 04:40 UTCEPSS rescore
  12. 2026-08-31 00:38 UTCEG score recompute
  13. 2026-08-31 00:38 UTCVendor advisory
  14. 2026-08-30 19:17 UTCEPSS rescore
  15. 2026-08-30 12:44 UTCEG score recompute
  16. 2026-08-30 12:44 UTCVendor advisory
  17. 2026-08-30 01:22 UTCEPSS rescore
  18. 2026-08-30 00:50 UTCEG score recompute
  19. 2026-08-30 00:50 UTCVendor advisory
  20. 2026-08-28 21:42 UTCEPSS rescore
  21. 2026-08-27 22:10 UTCEG score recompute
  22. 2026-08-27 22:10 UTCVendor advisory
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-27 10:16 UTCVendor advisory
  25. 2026-08-26 19:57 UTCEG score recompute
  26. 2026-08-26 19:57 UTCVendor advisory
  27. 2026-08-26 14:46 UTCEPSS rescore
  28. 2026-08-26 07:23 UTCVendor advisory
  29. 2026-08-25 19:29 UTCEG score recompute
  30. 2026-08-25 19:29 UTCVendor advisory
  31. 2026-08-25 13:49 UTCEPSS rescore
  32. 2026-08-25 07:35 UTCVendor advisory
  33. 2026-08-24 19:39 UTCEG score recompute
  34. 2026-08-24 19:39 UTCVendor advisory
  35. 2026-08-24 07:45 UTCVendor advisory
  36. 2026-08-23 19:52 UTCVendor advisory
  37. 2026-08-23 07:58 UTCEG score recompute
  38. 2026-08-23 07:58 UTCVendor advisory
  39. 2026-08-23 00:19 UTCEPSS rescore
  40. 2026-08-22 20:05 UTCVendor advisory
  41. 2026-08-22 08:11 UTCEG score recompute
  42. 2026-08-22 08:11 UTCVendor advisory
  43. 2026-08-21 23:49 UTCEPSS rescore
  44. 2026-08-21 20:17 UTCVendor advisory
  45. 2026-08-21 08:23 UTCEG score recompute
  46. 2026-08-21 08:23 UTCVendor advisory
  47. 2026-08-20 22:55 UTCEPSS rescore
  48. 2026-08-20 20:30 UTCVendor advisory
  49. 2026-08-20 08:36 UTCVendor advisory
  50. 2026-08-19 20:42 UTCEG score recompute
  51. 2026-08-19 20:42 UTCVendor advisory
  52. 2026-08-19 17:04 UTCEPSS rescore
  53. 2026-08-19 08:41 UTCVendor advisory
  54. 2026-08-18 20:47 UTCEG score recompute
  55. 2026-08-18 20:47 UTCVendor advisory
  56. 2026-08-18 13:48 UTCEPSS rescore
  57. 2026-08-18 08:53 UTCVendor advisory
  58. 2026-08-17 20:26 UTCEG score recompute
  59. 2026-08-17 20:26 UTCVendor advisory
  60. 2026-08-17 13:47 UTCEPSS rescore
  61. 2026-08-17 07:01 UTCVendor advisory
  62. 2026-08-16 19:08 UTCEG score recompute
  63. 2026-08-16 19:08 UTCVendor advisory
  64. 2026-08-16 14:56 UTCEPSS rescore
  65. 2026-08-16 06:54 UTCEG score recompute
  66. 2026-08-16 06:54 UTCVendor advisory
  67. 2026-08-16 02:14 UTCEPSS rescore
  68. 2026-08-15 19:01 UTCVendor advisory
  69. 2026-08-15 07:07 UTCEG score recompute
  70. 2026-08-15 07:07 UTCVendor advisory
  71. 2026-08-15 01:30 UTCEPSS rescore
  72. 2026-08-14 19:04 UTCVendor advisory
  73. 2026-08-14 07:11 UTCEG score recompute
  74. 2026-08-14 07:11 UTCVendor advisory
  75. 2026-08-13 22:00 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-59898?
CVE-2026-59898 is a high vulnerability published on July 22, 2026. Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, ab attacker can force WebSocket upgrade via the lax V07 (or V08) handshaker by sending Sec-WebSocket-Version: 7 and omitting Connection: Upgrade / Upgrade: websocket headers,…
When was CVE-2026-59898 disclosed?
CVE-2026-59898 was first published in the National Vulnerability Database on July 22, 2026, with the most recent update on August 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59898 actively exploited?
CVE-2026-59898 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 83.7% of all scored CVEs.
What is the CVSS score of CVE-2026-59898?
CVE-2026-59898 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-59898?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59898, 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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