---
title: "CVE-2026-94450: s2n-quic - Denial of Service"
description: "s2n-quic <= 1.88.0 contains a denial of service caused by improper validation of Destination Connection ID length in server endpoints configured to send Retry packets, letting unauthenticated remote attackers shut down the server via crafted UDP datagram."
url: https://panop.io/threat-heartbeat/CVE-2026-94450/
---

# CVE-2026-94450 s2n-quic - Denial of Service

s2n-quic <= 1.88.0 contains a denial of service caused by improper validation of Destination Connection ID length in server endpoints configured to send Retry packets, letting unauthenticated remote attackers shut down the server via crafted UDP datagram.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

1.94% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-94450)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published

22 September 2026

Updated

15 October 2026

Weakness

[CWE-1284](https://cwe.mitre.org/data/definitions/1284.html)

## Vendor fix

Upgrade to version v1.89.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-94450](https://nvd.nist.gov/vuln/detail/CVE-2026-94450)
- [https://aws.amazon.com/security/security-bulletins/2026-116-aws/](https://aws.amazon.com/security/security-bulletins/2026-116-aws/)
- [https://github.com/aws/s2n-quic/releases/tag/v1.89.0](https://github.com/aws/s2n-quic/releases/tag/v1.89.0)
- [https://github.com/aws/s2n-quic/security/advisories/GHSA-5rw2-6x5m-v22x](https://github.com/aws/s2n-quic/security/advisories/GHSA-5rw2-6x5m-v22x)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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