PatchSiren cyber security CVE debrief

CVE-2026-10740 Amazon Web Services CVE debrief

CVE-2026-10740 is a medium-severity vulnerability in s2n-quic, a QUIC implementation. The vulnerability is caused by unbounded memory allocation in the CRYPTO frame reassembler, which may allow an unauthenticated remote actor to cause a denial of service (degraded availability) by sending crafted QUIC Initial packets.

Vendor: Amazon Web Services
Product: s2n-quic
CVSS: MEDIUM 6.9
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-10
Original CVE updated: 2026-06-10
Advisory published: 2026-06-10
Advisory updated: 2026-06-10

Who should care

Users of s2n-quic before version 1.8.2 should upgrade to version 1.8.2 to remediate this issue.

Technical summary

The vulnerability has a CVSS score of 6.9 and is classified as CWE-770. It was published on 2026-06-10T19:16:32.470Z and last modified on 2026-06-10T20:19:35.917Z.

Defensive priority

MEDIUM

Recommended defensive actions

Upgrade to s2n-quic version 1.8.2 or later.

Evidence notes

The CVE record and NVD detail can be found at [cve-org] and [nvd], respectively. Additional information can be found at [ref-4], [ref-5], and [ref-6].

Sources and references

Verified primary and authoritative sources

CVE-2026-10740 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2026-10740

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2026-10740 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2026-10740

NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Source reference
Unverified legacy reference

URL: https://aws.amazon.com/security/security-bulletins/2026-042-aws/

ff89ba41-3aa1-4d27-914a-91399e9639e5
Source reference
Unverified legacy reference

URL: https://github.com/aws/s2n-quic/releases/tag/v1.82.0

ff89ba41-3aa1-4d27-914a-91399e9639e5
Source reference
Unverified legacy reference

URL: https://github.com/aws/s2n-quic/security/advisories/GHSA-9q54-f358-3fqf

ff89ba41-3aa1-4d27-914a-91399e9639e5

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.