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
65%
KEV
Not listed

Published

March 27, 2026

Last Modified

September 15, 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(17)

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

Patch Availability(9)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhoai/odh-trustyai-service-rhel9:17881986812026-09-08redhat
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.el8eap2026-05-18redhat
redhateap8-netty-transport-native-epoll-0:4.1.132-1.Final_redhat_00001.1.el9eap2026-05-18redhat
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 / 41× 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 132 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

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 September 15, 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 35.2% 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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