CVE-2026-33870 | Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing

Exp

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.

Published: 2026-03-27 Last update: 2026-03-30 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33870 is rated Exploit Available (50/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-33870

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-33870

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-28 — 0.03% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33870

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-33870

GitHub Security Advisory for CVE-2026-33870

GHSA-pwqr-wmgm-9rr8 · Severity: high · Ecosystem: maven — Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing

OS Trackers for CVE-2026-33870

vendor priority summary link
debian not yet assigned CVE-2026-33870 not yet assigned priority: Debian including 1 source packages (netty), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-33870
redhat high — https://access.redhat.com/security/cve/CVE-2026-33870
suse high CVE-2026-33870 severity important: SUSE including 10 source package names (netty-4.1.132-1.1, netty-4.1.132-150200.4.43.1, …), 26 product×package rows across 16 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (16 product lines)): Known Not Affected 14, Fixed 12. https://www.suse.com/security/cve/CVE-2026-33870/
ubuntu medium CVE-2026-33870 medium priority: Ubuntu including 1 source packages (netty), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): needs-triage 8. https://ubuntu.com/security/CVE-2026-33870

Affected software / configurations for CVE-2026-33870

Vendor Product Version Raw CPE
netty netty < 4.1.132 cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
netty netty >= 4.2.0, < 4.2.10 cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

References for CVE-2026-33870

cvelogic Threat Intelligence