CVE-2026-55833

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). 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, secondary
Trending — Patch released this week
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: None knownExposed: 0

A fix is available — apply it.

Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has exceeded maxHeaderSize and marked the frame truncated in SpdyFrameCodec, allowing a remote peer to send a small compressed HEADERS block that expands into much larger raw header data and causes compression-amplified CPU and allocation churn. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

July 20, 2026

Last Modified

July 23, 2026

Advisory Details (5)

Auto-updated Jul 21, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c
github_release Patch Available

netty-4.2.16.Final

Patch available: netty/netty netty-4.2.16.Final

https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
github_release Patch Available

netty-4.1.136.Final

Patch available: netty/netty netty-4.1.136.Final

https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
github_commit Patch Available

commit bb2ff68a1fb7 (netty/netty)

Patch available: netty/netty netty-4.1.136.Final (contains commit bb2ff68a1fb7)

https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
github_commit Patch Available

commit 5b68c61f37aa (netty/netty)

Patch available: netty/netty netty-4.2.16.Final (contains commit 5b68c61f37aa)

https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b

Vendor Advisories for CVE-2026-55833(9)

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-http2026-09-10redhat
redhatrhoai/odh-trustyai-service-rhel9:17881986812026-09-08redhat
redhatdevspaces/pluginregistry-rhel9:17877597232026-09-01redhat

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-http4.1.0.Final ... 4.1.99.Final (136 versions)4.1.136.Final—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 87× 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 157 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-55833?
CVE-2026-55833 is a high vulnerability published on July 20, 2026. Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has exceeded maxHeaderSize and marked the frame truncated in…
When was CVE-2026-55833 disclosed?
CVE-2026-55833 was first published in the National Vulnerability Database on July 20, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55833 actively exploited?
CVE-2026-55833 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 64.3% of all scored CVEs.
What is the CVSS score of CVE-2026-55833?
CVE-2026-55833 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-55833?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55833, 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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