What is CVE-2026-16756?

CVE-2026-16756 is a high-severity vulnerability in AWS Aws-Smithy-Http-Server, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-23.

How severe is CVE-2026-16756?

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

Resource exhaustion in AWS Aws-Smithy-Http-Server

CVE-2026-16756

Missing connection and header-read timeouts and the absence of a concurrent-connection cap in the default serve() path of Amazon aws-smithy-http-server might allow remote attackers to cause a denial of service by opening many connections and sending partial requests that are never completed, exhausting server sockets and tasks. To mitigate this issue, users should upgrade to aws-smithy-http-server 0.66.5 or later.

EPSS: 0.007 (52.6th percentile) — read the EPSS interpretation.

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.

Affected products

Aws Aws-smithy-http-server — versions 0

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

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-2026-16756?: CVE-2026-16756 is a high-severity vulnerability in AWS Aws-Smithy-Http-Server, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-23.
How severe is CVE-2026-16756?: High severity. CVSS v3 base score is 7.5 out of 10.