CVE-2026-44892 | Netty has a Vulnerable Default Configuration Which Leads to Denial of Service via Unbounded HTTP/3 Header Size

Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, the default configuration of the `Http3ConnectionHandler` in the Netty HTTP/3 codec lacks an enforced maximum header size limit. When a peer does not explicitly specify `HTTP3_SETTINGS_MAX_FIELD_SECTION_SIZE`, the implementation defaults to an unbounded limit. This insecure default configuration allows a malicious client or server to send an enormous number of headers, leading to a memory exhaustion Denial of Service via an `OutOfMemoryError`. Version 4.2.15.Final contains a patch.

Published: 2026-06-12 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-44892 is rated Moderate Risk (43.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.49%). Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2026-44892

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 2026-06-15 0.04% 0.49% +0.45%
2 2026-06-12 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-44892

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:N/A:H 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-44892

GitHub Security Advisory for CVE-2026-44892

GHSA-c2rx-5r8w-8xr2 · Severity: high · Ecosystem: maven — Netty has a Vulnerable Default Configuration Which Leads to Denial of Service via Unbounded HTTP/3 Header Size

OS Trackers for CVE-2026-44892

vendor priority summary link
debian not yet assigned CVE-2026-44892 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-2026-44892
ubuntu medium CVE-2026-44892 medium priority: Ubuntu including 1 source packages (netty), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream): needs-triage 8. https://ubuntu.com/security/CVE-2026-44892

Affected software / configurations for CVE-2026-44892

Vendor Product Version Raw CPE
netty netty >= 4.2.0, < 4.2.15 cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

References for CVE-2026-44892

cvelogic Threat Intelligence