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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
AWS aws-smithy-http-server unaffected
Version Status Constraints
0 affected ≤ 0.66.4

No data.

No data.

No data.

Project Subscriptions

Vendors Products
Aws Subscribe
Aws-smithy-http-server Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://aws.amazon.com/security/security-bulletins/2026-064-aws/ cve-icon
https://crates.io/crates/aws-smithy-http-server/0.66.5 cve-icon
https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-jvxp-qmx7-gjpx cve-icon
History

Thu, 23 Jul 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service
First Time appeared Aws
Aws aws-smithy-http-server
Weaknesses CWE-770
CPEs cpe:2.3:a:aws:aws-smithy-http-server:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws aws-smithy-http-server
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': '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'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-07-23T19:03:57.617Z

Reserved: 2026-07-23T13:10:13.818Z

Link: CVE-2026-16756

cve-icon Vulnrichment

Updated: 2026-07-23T19:03:52.252Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses