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TI-2026-63436 Aliases CVE-2026-94450

Potential denial of service when configured to send Retry packets in s2n-quic

Priority MEDIUM 47CWE-1284Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-617.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01944 80th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
AWSs2n-quicup to 1.88.0—No fix listedCNA
  • s2n-quic VendorAWS Affected up to 1.88.0 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-94450
  2. 2026-10-20 Weakness changed · CNA

References

Patch 1

Advisory 1

Other 1

  • TI-2026-23989 crypto: algif_aead - Revert to operating out-of-place KEVCVSS 3.1HIGH 7.8
  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2024-18648 Amazon AWS Amplify CLI before 12.10.1 incorrectly configures the role trust policy of IAM… CVSS 3.1CRITICAL 9.8
  • TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
  • TI-2025-03847 Input validation issue in AWS Amplify Studio UI component properties CVSS 4.0CRITICAL 9.0
  • TI-2026-11603 HTTP/2 Stream Parser Confusion Body-Inspection Bypass in Amazon CloudFront with AWS WAF CVSS 4.0HIGH 7.9
See all 383 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences