---
id: CVE-2026-102479
title: >-
  In Eclipse Vert.x versions [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0],
  the Vert.x HTTP/1.x decoder uses a canonicalization for well known HTTP
  headers, the canonicalization process interprets well crafted headers as
  headers of thi…
summary: >-
  In Eclipse Vert.x versions [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0],
  the Vert.x HTTP/1.x decoder uses a canonicalization for well known HTTP
  headers, the canonicalization process interprets well crafted headers as
  headers of thi…
severity: high
cvss: 8.7
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'
vendor: Eclipse Foundation
product: Eclipse Vert.x
affected:
  - eclipse_vert.x >= 5.0.0 <= 5.0.12
  - eclipse_vert.x >= 5.1.0 <= 5.1.9
  - eclipse_vert.x 5.2.0
published: '2026-10-14'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T14:41:34.110'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102479'
references:
  - url: >-
      https://github.com/eclipse-vertx/vert.x/security/advisories/GHSA-ch7p-g5pm-3gqx
    label: emo@eclipse.org
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/352'
    label: emo@eclipse.org
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-10-14T19:49:57.603Z'
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T18:23:27.862590Z'
epss: 0.0027
epssPercentile: 0.19034
---

## Overview

In Eclipse Vert.x versions [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x HTTP/1.x decoder uses a canonicalization for well known HTTP headers, the canonicalization process interprets well crafted headers as headers of this list, allowing for instance Content-Xength to be interpeted as Content-Length.



This can be exploited for request smuggling purpose.



The impacted component is io.vertx:vertx-core.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.