Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service (CVE-2026-16756) | HOL Guard CVE

High · CVSS 7.5CVE-2026-16756

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

Answer in brief

CVE-2026-16756 records a High severity (CVSS 7.5) vulnerability in Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service. The current sources do not mark it as known exploited. The current feed maps AWS/aws-smithy-http-server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 23, 2026Updated Aug 12, 2026Source checked Sep 27, 2026First seen by HOL Aug 12, 2026Material review Aug 12, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps AWS/aws-smithy-http-server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
AWS/aws-smithy-http-servergeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for AWS/aws-smithy-http-server.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Jul 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 12, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.