CVE-2026-16756

Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service

State: Published
Severity: 8.7 High
Published: Jul 23, 2026
Updated: Aug 12, 2026
Reserved: Jul 23, 2026

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Description

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.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	AMZN
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	AMZN

Weaknesses

CWE-770 Allocation of resources without limits or throttling

Affected Products

Product	Versions
aws-smithy-http-serverAWS	0.66.4 and earlierAffected

References

https://crates.io/crates/aws-smithy-http-server/0.66.5release-notespatch
https://aws.amazon.com/security/security-bulletins/2026-064-aws/vendor-advisory
https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-jvxp-qmx7-gjpxrelease-notes

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