CVE-2026-33870

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 51% 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: cna:github_m, epss
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: 0.7%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

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, Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks. Versions 4.1.132.Final and 4.2.10.Final fix the issue.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

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%
Automatability100% × 15%
EPSS PROB
0.7%
EPSS %ILE
51st
KEV
Not listed

Published

March 27, 2026

Last Modified

September 15, 2026

Advisory Details (10)

Auto-updated Jul 1, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: github, redhat.
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
generic

RFC 9110: HTTP Semantics | RFC Editor

https://www.rfc-editor.org/rfc/rfc9110
generic🔴 Active Exploitation

Funky chunks – addendum: a few more dirty tricks | w4ke.info

https://w4ke.info/2025/10/29/funky-chunks-2.html
generic🔴 Active Exploitation

Funky chunks: abusing ambiguous chunk line terminators for request smuggling | w4ke.info

https://w4ke.info/2025/06/18/funky-chunks.html
github Patch Available🟡 PoC Available

RFC violation: HTTP Request Smuggling primitive via Chunked Extension Quoted-String Parsing · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-pwqr-wmgm-9rr8

Vendor Advisories for CVE-2026-33870(18)

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 / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/odh-trustyai-service-rhel9:17881986812026-09-08redhat
redhatnetty-codec-http2026-07-02redhat
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
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 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-codec-http4.2.0.Alpha1 ... 4.2.9.Final (20 versions)
  • every version up to 4.1.132.Final: fixed in 4.1.132.Final
  • 4.2.0.Alpha1 up to 4.2.10.Final: fixed in 4.2.10.Final
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 34× 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 143 total refreshes for this CVE.

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

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

Frequently asked(5)

What is CVE-2026-33870?
CVE-2026-33870 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, Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks. Versions 4.1.132.Final and 4.2.10.Final fix…
When was CVE-2026-33870 disclosed?
CVE-2026-33870 was first published 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-2026-33870 actively exploited?
CVE-2026-33870 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (51st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33870?
CVE-2026-33870 has a CVSS base score of 7.5 (the CNA's own assessment, by github_m; NVD's own analysis pending).
How do I remediate CVE-2026-33870?
A fix for CVE-2026-33870 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33870 are linked in the Vendor Advisories panel on this page.

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