CVE-2026-42579

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 1.0%, top 40% 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
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: 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, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
72(Attend)
EG Risk 72/100SSVC: 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
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
60%
KEV
Not listed

Published

May 13, 2026

Last Modified

August 21, 2026

Advisory Details (1)

Auto-updated Aug 1, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fm

Vendor Advisories for CVE-2026-42579(10)

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

Patch Availability(7)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibnetty-java (1:4.0.34-1ubuntu0.1~esm4) @ xenial2026-08-24ubuntu
redhatnetty-codec-dns2026-08-12redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el7eap2026-08-11redhat
redhatdevspaces/multicluster-redirector-rhel9:17829890272026-07-08redhat
redhatcryostat/jfr-datasource-rhel9:4.2.0-102026-06-22redhat
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

(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-dns4.1.0.Beta1 ... 4.1.99.Final (148 versions)4.1.133.Final—

Weakness Classification(4)

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 15× in last 7d / 113× 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 229 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42579?
CVE-2026-42579 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, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the…
When was CVE-2026-42579 disclosed?
CVE-2026-42579 was first published in the National Vulnerability Database on May 13, 2026, with the most recent update on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42579 actively exploited?
CVE-2026-42579 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 39.6% of all scored CVEs.
What is the CVSS score of CVE-2026-42579?
CVE-2026-42579 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-42579?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42579, 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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