CVE-2026-44249

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 1.0%, top 39% 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, secondary
Trending — 3 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.1Exploit: None knownExposed: 0

A fix is available — apply it.

Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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
Severity81% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
61%
KEV
Not listed

Published

June 8, 2026

Last Modified

August 20, 2026

Advisory Details (3)

Auto-updated Jun 12, 2026
Patch available. Sources: github_release, github.
github Patch Available

IPv6 Subnet Filter Bypass via Incorrect Comparator Masking · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-3qp7-7mw8-wx86
github_release Patch Available

netty-4.2.15.Final

Patch available: netty/netty netty-4.2.15.Final

https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
github_release Patch Available

netty-4.1.135.Final

Patch available: netty/netty netty-4.1.135.Final

https://github.com/netty/netty/releases/tag/netty-4.1.135.Final

Vendor Advisories for CVE-2026-44249(17)

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

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnetty-handler2026-08-12redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el7eap2026-08-11redhat
redhateap8-wildfly-0:8.1.7.1-1.GA_redhat_00004.1.el9eap2026-08-03redhat
redhatio.netty/netty-handler:4.1.132.Final-redhat-000012026-08-03redhat
redhatdevspaces/jetbrains-ide-rhel9:17848305522026-07-29redhat
redhatcryostat/jfr-datasource-rhel9:4.2.0-132026-07-29redhat
redhatdevspaces/pluginregistry-rhel9:17829893672026-07-08redhat
redhatoffline-knowledge-portal/rhokp-rhel9:17822393702026-06-23redhat

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-handler4.0.0.Alpha1 ... 4.1.99.Final (228 versions)4.1.135.Final—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 32× in last 7d / 132× 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 221 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-44249?
CVE-2026-44249 is a high vulnerability published on June 8, 2026. Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses…
When was CVE-2026-44249 disclosed?
CVE-2026-44249 was first published in the National Vulnerability Database on June 8, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-44249 actively exploited?
CVE-2026-44249 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 39.1% of all scored CVEs.
What is the CVSS score of CVE-2026-44249?
CVE-2026-44249 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-44249?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-44249, 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-2026-44249

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