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.

References

https://aws.amazon.com/security/security-bulletins/2026-116-aws/

https://github.com/aws/s2n-quic/security/advisories/GHSA-5rw2-6x5m-v22x

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

Details

Source: Mitre, NVD

Published: 2026-09-22

Updated: 2026-09-23

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

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

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.01944