CVE-2026-33871

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 1.1%, top 36% 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 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: 1%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of CONTINUATION frames. The server's lack of a limit on the number of CONTINUATION frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.

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%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
64%
KEV
Not listed

Published

March 27, 2026

Last Modified

August 18, 2026

Advisory Details (10)

Auto-updated Jul 3, 2026
Patch available. Sources: github, redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Important. A Common

https://access.redhat.com/errata/RHSA-2026:18055
redhat Patch Available

Affected: Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common

https://access.redhat.com/errata/RHSA-2026:18054
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:17789
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:17668
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:14276
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:14272
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:13571
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:10184
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:10175
github Patch Available

HTTP/2 CONTINUATION Frame Flood Denial of Service · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-w9fj-cfpg-grvv

Vendor Advisories for CVE-2026-33871(16)

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-codec-http22026-07-02redhat
redhatcryostat/jfr-datasource-rhel9:4.2.0-92026-05-26redhat
redhateap8-netty-transport-native-epoll-0:4.1.132-1.Final_redhat_00001.1.el9eap2026-05-18redhat
redhateap8-netty-transport-native-epoll-0:4.1.132-1.Final_redhat_00001.1.el8eap2026-05-18redhat
redhatnetty-codec-http-4.1.100.Final.jar2026-05-18redhat
redhatpatch2026-05-04redhat
redhatdevspaces/server-rhel9:17767964452026-04-23redhat
redhatrhoai/odh-modelmesh-rhel9:17767568342026-04-23redhat

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-codec-http24.2.0.Alpha1 ... 4.2.9.Final (21 versions)4.2.11.Final—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 64× 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.

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

Frequently asked(5)

What is CVE-2026-33871?
CVE-2026-33871 is a high vulnerability published on March 27, 2026. Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of CONTINUATION frames. The server's lack of a limit on the number of…
When was CVE-2026-33871 disclosed?
CVE-2026-33871 was first published in the National Vulnerability Database on March 27, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33871 actively exploited?
CVE-2026-33871 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 36.2% of all scored CVEs.
What is the CVSS score of CVE-2026-33871?
CVE-2026-33871 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-33871?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33871, 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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