CVE-2026-42584

CRITICALNVD 9.17.3▼
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.3 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 66% 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 weekElevated
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

A fix is available — apply it.

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS v3
9.1
EG Score
7.3(medium)
EPSS
49.9%
KEV
Not listed

Published

May 13, 2026

Last Modified

July 10, 2026

Advisory Details (1)

Auto-updated May 14, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

HttpClientCodec response desynchronization · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-57rv-r2g8-2cj3

Vendor Advisories for CVE-2026-42584(6)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibnetty-java (1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1) @ trusty2026-06-29ubuntu
redhatcryostat/jfr-datasource-rhel9:4.2.0-102026-06-22redhat
redhatnetty-codec-http2026-06-10redhat
redhatpatch2026-06-10redhat
redhatdevspaces/server-rhel9:17806949942026-06-10redhat

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
io.netty:netty-codec-http4.0.0.Alpha1 ... 4.1.99.Final (226 versions)4.1.133.Final—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 12× in last 7d / 67× 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 131 total refreshes for this CVE.

  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-10 12:26 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  3. 2026-07-10 12:12 UTCMITRE cvelistV5CVSS v3 → 7.3 · severity → HIGH
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-09 13:52 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  6. 2026-07-08 15:15 UTCEPSS rescore
  7. 2026-07-07 13:46 UTCEPSS rescore
  8. 2026-07-06 16:27 UTCEPSS rescore
  9. 2026-07-06 16:27 UTCEPSS rescore
  10. 2026-07-06 02:23 UTCEPSS rescore
  11. 2026-07-06 02:23 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-03 22:12 UTCMITRE cvelistV5CVSS v3 → 7.3 · severity → HIGH
  15. 2026-07-01 15:06 UTCEPSS rescore
  16. 2026-06-30 23:22 UTCEPSS rescore
  17. 2026-06-30 04:33 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  18. 2026-06-29 22:13 UTCEG score recompute
  19. 2026-06-29 22:13 UTCVendor advisory
  20. 2026-06-29 14:06 UTCEPSS rescore
  21. 2026-06-28 14:07 UTCEPSS rescore
  22. 2026-06-28 11:44 UTCEG score recompute
  23. 2026-06-28 11:44 UTCVendor advisory
  24. 2026-06-28 04:56 UTCEPSS rescore
  25. 2026-06-27 23:23 UTCEG score recompute
Show 75 more
  1. 2026-06-27 23:23 UTCVendor advisory
  2. 2026-06-27 08:50 UTCEG score recompute
  3. 2026-06-27 08:50 UTCVendor advisory
  4. 2026-06-27 03:08 UTCEPSS rescore
  5. 2026-06-26 20:28 UTCEG score recompute
  6. 2026-06-26 20:28 UTCVendor advisory
  7. 2026-06-25 19:35 UTCEG score recompute
  8. 2026-06-25 19:35 UTCVendor advisory
  9. 2026-06-25 13:49 UTCEPSS rescore
  10. 2026-06-25 13:49 UTCEPSS rescore
  11. 2026-06-24 14:05 UTCEPSS rescore
  12. 2026-06-23 21:33 UTCEPSS rescore
  13. 2026-06-22 14:25 UTCEPSS rescore
  14. 2026-06-22 14:25 UTCEPSS rescore
  15. 2026-06-21 14:56 UTCEPSS rescore
  16. 2026-06-21 14:56 UTCEPSS rescore
  17. 2026-06-21 01:59 UTCEPSS rescore
  18. 2026-06-19 19:25 UTCEPSS rescore
  19. 2026-06-18 17:52 UTCEPSS rescore
  20. 2026-06-18 17:52 UTCEPSS rescore
  21. 2026-06-17 17:53 UTCEPSS rescore
  22. 2026-06-17 14:27 UTCEG score recompute
  23. 2026-06-17 14:27 UTCVendor advisory
  24. 2026-06-16 22:31 UTCEG score recompute
  25. 2026-06-16 22:31 UTCVendor advisory
  26. 2026-06-16 17:52 UTCEPSS rescore
  27. 2026-06-16 00:38 UTCEG score recompute
  28. 2026-06-16 00:38 UTCVendor advisory
  29. 2026-06-15 17:49 UTCEPSS rescore
  30. 2026-06-15 00:27 UTCEG score recompute
  31. 2026-06-15 00:27 UTCVendor advisory
  32. 2026-06-14 12:04 UTCEG score recompute
  33. 2026-06-14 12:04 UTCVendor advisory
  34. 2026-06-13 23:42 UTCEG score recompute
  35. 2026-06-13 23:42 UTCVendor advisory
  36. 2026-06-13 23:00 UTCEPSS rescore
  37. 2026-06-13 02:18 UTCEG score recompute
  38. 2026-06-13 02:18 UTCVendor advisory
  39. 2026-06-12 23:12 UTCEPSS rescore
  40. 2026-06-12 23:12 UTCEPSS rescore
  41. 2026-06-12 13:56 UTCEG score recompute
  42. 2026-06-12 13:56 UTCVendor advisory
  43. 2026-06-12 01:35 UTCEG score recompute
  44. 2026-06-12 01:35 UTCVendor advisory
  45. 2026-06-11 14:00 UTCEPSS rescore
  46. 2026-06-11 13:13 UTCEG score recompute
  47. 2026-06-11 13:13 UTCVendor advisory
  48. 2026-06-11 00:52 UTCEG score recompute
  49. 2026-06-11 00:52 UTCVendor advisory
  50. 2026-06-10 22:18 UTCEPSS rescore
  51. 2026-06-10 13:22 UTCEPSS rescore
  52. 2026-06-10 13:22 UTCEPSS rescore
  53. 2026-06-10 12:30 UTCEG score recompute
  54. 2026-06-10 12:30 UTCVendor advisory
  55. 2026-06-10 00:08 UTCEG score recompute
  56. 2026-06-10 00:08 UTCVendor advisory
  57. 2026-06-09 11:47 UTCEG score recompute
  58. 2026-06-09 11:47 UTCVendor advisory
  59. 2026-06-08 23:25 UTCEG score recompute
  60. 2026-06-08 23:25 UTCVendor advisory
  61. 2026-06-08 14:17 UTCEPSS rescore
  62. 2026-06-08 14:17 UTCEPSS rescore
  63. 2026-06-08 11:02 UTCEG score recompute
  64. 2026-06-07 22:41 UTCEG score recompute
  65. 2026-06-07 15:25 UTCEPSS rescore
  66. 2026-06-07 15:25 UTCEPSS rescore
  67. 2026-06-07 10:20 UTCEG score recompute
  68. 2026-06-06 21:59 UTCEG score recompute
  69. 2026-06-06 09:38 UTCEG score recompute
  70. 2026-06-05 22:47 UTCEPSS rescore
  71. 2026-06-05 21:16 UTCEG score recompute
  72. 2026-06-05 08:55 UTCEG score recompute
  73. 2026-06-05 06:10 UTCEPSS rescore
  74. 2026-06-05 06:10 UTCEPSS rescore
  75. 2026-06-04 20:33 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-42584?
CVE-2026-42584 is a critical vulnerability published on May 13, 2026. Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103,…
When was CVE-2026-42584 disclosed?
CVE-2026-42584 was first published in the National Vulnerability Database on May 13, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42584 actively exploited?
CVE-2026-42584 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 49.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42584?
CVE-2026-42584 has a CVSS v3 base score of 9.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.3.
How do I remediate CVE-2026-42584?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42584, 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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