AIOHTTP Affected by Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector (CVE-2026-34513) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-34513GHSA-HCC4-C3V8-RX92

AIOHTTP Affected by Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector

Answer in brief

CVE-2026-34513 records a Unknown severity vulnerability in AIOHTTP Affected by Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector. The current sources do not mark it as known exploited. The current feed maps aiohttp (pypi). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

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

Published Apr 1, 2026Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Sep 10, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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 aiohttp (pypi). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
aiohttppypi	>=0 <3.13.4	3.13.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for aiohttp.
Review the reported fix. Update aiohttp to 3.13.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Apr 1, 2026
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Sep 10, 2026

Sources and claim methodology

Upstream source description

### Summary An unbounded DNS cache could result in excessive memory usage possibly resulting in a DoS situation. ### Impact If an application makes requests to a very large number of hosts, this could cause the DNS cache to continue growing and slowly use excessive amounts of memory. ----- Patch: https://github.com/aio-libs/aiohttp/commit/c4d77c3533122be353b8afca8e8675e3b4cbda98

Quoted source text, attributed separately from HOL analysis.