CVE-2026-42583

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% 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
7.5EG
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: Elevated riskExposed: 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, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if compressedLength == 1 - to force that allocation. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

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%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

May 13, 2026

Last Modified

May 18, 2026

Advisory Details (1)

Auto-updated May 13, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Lz4FrameDecoder resource exhaustion · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6

Vendor Advisories for CVE-2026-42583(4)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnetty-codec-compression2026-08-12redhat
redhatdevspaces/multicluster-redirector-rhel9:17829890272026-07-08redhat
redhatpatch2026-07-02redhat

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

(6 across 5 ecosystems)
Maven(2)
PackageVulnerable rangeFixed inDependents
io.netty:netty-codec4.0.0.Alpha1 ... 4.1.99.Final (226 versions)4.1.133.Final—
io.netty:netty-codec-compression4.2.0.Alpha3 ... 4.2.9.Final (21 versions)4.2.13.Final—
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)——

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 52× 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 165 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-42583?
CVE-2026-42583 is a high 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, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if…
When was CVE-2026-42583 disclosed?
CVE-2026-42583 was first published in the National Vulnerability Database on May 13, 2026, with the most recent update on May 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42583 actively exploited?
CVE-2026-42583 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 61.6% of all scored CVEs.
What is the CVSS score of CVE-2026-42583?
CVE-2026-42583 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-42583?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42583, 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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