s2nQUIC (<1.89) DOS via crafted UDP DCI length
CVE-2026-94450 Published on September 22, 2026
Potential denial of service when configured to send Retry packets in s2n-quic
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.
Vulnerability Analysis
CVE-2026-94450 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Types
Improper Validation of Specified Quantity in Input
The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.
What is an assertion failure Vulnerability?
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
CVE-2026-94450 has been classified to as an assertion failure vulnerability or weakness.
Products Associated with CVE-2026-94450
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Affected Versions
AWS s2n-quic:- Before and including 1.88.0 is affected.