CVE-2026-94450

High

Description

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.

SeverityHigh

CVSS7.5

Exploit probability—

ProductAws S2n-quic

PublishedSep 22, 2026

First seenSep 22, 2026

Weakness typeCWE-1284CWE-1284 CWE-617CWE-617

How to fix

Patches

github.com/aws/s2n-quic/releases/tag/v1.89.0

Vendor advisories

aws.amazon.com/security/security-bulletins/2026-116-aws/
github.com/aws/s2n-quic/security/advisories/GHSA-5rw2-6x5m-v22x

Affected products

Product	Affected versions	Fixed in
AWS s2n-quic	v ≤ 1.88.0	—

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