CVE-2026-42578

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 1.1%, top 37% 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: 1.2%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

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 HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders without any CRLF validation. This allows an attacker who can influence the outbound headers to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
50
EG Risk 50/100

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%
Automatability0% × 15%
EPSS PROB
1.2%
EPSS %ILE
66th
KEV
Not listed

Published

May 13, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated May 18, 2026
🔬 Proof of concept available. Patch available. Sources: github.
githubMentions a patch (unverified)🟡 PoC Available

HTTP Header Injection via HttpProxyHandler Disabled Validation in Netty · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr

Vendor Advisories for CVE-2026-42578(20)

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

Patch Availability(13)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibnetty-java (1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1) @ trusty2026-09-18ubuntu
redhatnetty-handler-proxy2026-09-10redhat
redhatrhoai/odh-trustyai-service-rhel9:17881986812026-09-08redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el8eap2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el9eap2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el7eap2026-08-11redhat
redhatio.netty/netty-handler-proxy:4.1.135.Final-redhat-000012026-08-03redhat
redhateap8-wildfly-0:8.1.7.1-1.GA_redhat_00004.1.el9eap2026-08-03redhat
redhatrhoai/odh-modelmesh-rhel9:17834438162026-07-21redhat
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 rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (16 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (12 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (7 versions)
  • every version on: no fix on record
—
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
io.netty:netty-handler-proxy4.2.0.Alpha1 ... 4.2.9.Final (23 versions)
  • every version up to 4.1.133.Final: fixed in 4.1.133.Final
  • 4.2.0.Alpha1 up to 4.2.13.Final: fixed in 4.2.13.Final
—

Weakness Classification(2)

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

Additional Vendor Advisories

(6)

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 8× in last 7d / 32× 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 228 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42578?
CVE-2026-42578 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, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using…
When was CVE-2026-42578 disclosed?
CVE-2026-42578 was first published on May 13, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42578 actively exploited?
CVE-2026-42578 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.2% probability of exploitation in the next 30 days (66th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42578?
CVE-2026-42578 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-42578?
A fix for CVE-2026-42578 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42578 are linked in the Vendor Advisories panel on this page.

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