---
id: CVE-2026-94450
title: >-
  Improper validation of the Destination Connection ID length in s2n-quic 1.88.0
  and earlier may allow an unauthenticated remote user to cause a denial of
  service by shutting down a server endpoint via a single crafted UDP datagram
summary: >-
  Improper validation of the Destination Connection ID length in s2n-quic 1.88.0
  and earlier may allow an unauthenticated remote user to cause a denial of
  service by shutting down a server endpoint via a single crafted UDP datagram.
  Only s…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1284
vendor: AWS
product: s2n-quic
affected:
  - s2n-quic <= 1.88.0
published: '2026-09-22'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T17:58:37.490'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94450'
references:
  - url: 'https://aws.amazon.com/security/security-bulletins/2026-116-aws/'
    label: ff89ba41-3aa1-4d27-914a-91399e9639e5
  - url: 'https://github.com/aws/s2n-quic/releases/tag/v1.89.0'
    label: ff89ba41-3aa1-4d27-914a-91399e9639e5
  - url: 'https://github.com/aws/s2n-quic/security/advisories/GHSA-5rw2-6x5m-v22x'
    label: ff89ba41-3aa1-4d27-914a-91399e9639e5
tags:
  - nvd
  - cve.org
epss: 0.01944
epssPercentile: 0.79297
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T12:43:01.979928Z'
ingestedAt: '2026-09-22T21:11:40.327Z'
---

## Overview

Improper validation of the Destination Connection ID length in s2n-quic 1.88.0 and earlier may allow an unauthenticated remote user to cause a denial of service by shutting down a server endpoint via a single crafted UDP datagram. Only server endpoints specifically configured to send Retry packets are affected.



To remediate this issue, users should upgrade to version v1.89.0 or later.

## Remediation

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