What is CVE-2026-94450?

CVE-2026-94450 is a high-severity vulnerability in AWS S2n-Quic, classified under Improper Validation of Specified Quantity in Input. CVSS score: 7.5/10. Published 2026-09-22.

How severe is CVE-2026-94450?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in AWS S2n-Quic

CVE-2026-94450

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.

Published 2026-09-22.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

AWS S2n-Quic

Weakness classification (CWE)

CWE-1284 — Improper Validation of Specified Quantity in Input

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (release-notes, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (release-notes)

Frequently asked questions

What is CVE-2026-94450?: CVE-2026-94450 is a high-severity vulnerability in AWS S2n-Quic, classified under Improper Validation of Specified Quantity in Input. CVSS score: 7.5/10. Published 2026-09-22.
How severe is CVE-2026-94450?: High severity. CVSS v3 base score is 7.5 out of 10.