CVE-2026-94450
Potential denial of service when configured to send Retry packets in s2n-quic
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.
INFO
Published Date :
Sept. 22, 2026, 9:17 p.m.
Last Modified :
Sept. 22, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
ff89ba41-3aa1-4d27-914a-91399e9639e5
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 | ||||
| CVSS 4.0 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 | ||||
| CVSS 4.0 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 |
Solution
- Upgrade s2n-quic to version 1.89.0 or later.
- Ensure server endpoints are not configured to send Retry packets if unable to upgrade.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-94450.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-94450 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-94450
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-94450 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-94450 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by ff89ba41-3aa1-4d27-914a-91399e9639e5
Sep. 22, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-1284 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/94xxx/CVE-2026-94450.json">CVE-2026-94450</a> Added Reference https://aws.amazon.com/security/security-bulletins/2026-116-aws/ Added Reference https://github.com/aws/s2n-quic/releases/tag/v1.89.0 Added Reference https://github.com/aws/s2n-quic/security/advisories/GHSA-5rw2-6x5m-v22x