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 53% 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: 1%CVSS: 7.5Exploit: Elevated riskExposed: 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, 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
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

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%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

March 27, 2026

Last Modified

July 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(16)

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

Patch Availability(7)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnetty-codec-http2026-06-02redhat
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

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
io.netty:netty-codec-http4.2.0.Alpha1 ... 4.2.9.Final (20 versions)4.2.10.Final—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 39× 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. 2026-07-26 14:54 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-25 14:18 UTCEPSS rescore
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-24 14:17 UTCEPSS rescore
  6. 2026-07-24 14:17 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:09 UTCEG score recompute
  10. 2026-07-22 14:08 UTCEPSS rescore
  11. 2026-07-21 15:24 UTCEPSS rescore
  12. 2026-07-20 17:08 UTCEPSS rescore
  13. 2026-07-19 14:31 UTCEPSS rescore
  14. 2026-07-19 02:29 UTCEPSS rescore
  15. 2026-07-18 10:04 UTCEPSS rescore
  16. 2026-07-18 06:59 UTCOSV refresh
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-15 16:57 UTCEPSS rescore
  19. 2026-07-15 16:57 UTCEPSS rescore
  20. 2026-07-15 02:00 UTCEPSS rescore
  21. 2026-07-13 22:30 UTCEPSS rescore
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-13 06:13 UTCEPSS rescore
  24. 2026-07-12 05:46 UTCEPSS rescore
  25. 2026-07-11 08:27 UTCEPSS rescore
Show 14 more
  1. 2026-07-09 19:10 UTCEPSS rescore
  2. 2026-07-08 15:15 UTCEPSS rescore
  3. 2026-07-07 13:46 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-05 02:30 UTCEPSS rescore
  9. 2026-07-04 06:31 UTCEPSS rescore
  10. 2026-07-01 15:06 UTCEPSS rescore
  11. 2026-06-30 23:22 UTCEPSS rescore
  12. 2026-06-30 04:37 UTCEG score recompute
  13. 2026-06-30 04:37 UTCVendor advisory
  14. 2026-06-30 04:32 UTCNVD updatefirst tracked

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 in the National Vulnerability Database on March 27, 2026, with the most recent update on July 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 1% probability of exploitation in the next 30 days, which ranks it in the top 53.0% of all scored CVEs.
What is the CVSS score of CVE-2026-33870?
CVE-2026-33870 has a CVSS v4.0 base score of 7.5 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-33870?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33870, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-33870

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