# CVE-2026-69244: AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)

> A malicious server can trigger an out-of-bounds heap read in the aiohttp client parser, causing a denial of service.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 3 Aug 2026
- **Updated:** 4 Aug 2026
- **Also known as:** AZL-94553, CLEANSTART-2026-TB06618, CLSA-2026-1788347890, DEBIAN-CVE-2026-69244, ECHO-c0fa-407f-b85b, GHSA-cq5v-8q36-5273, MINI-276q-7f34-6q5v, MINI-332m-8jpm-x93v, MINI-5fj5-6ccq-3j4w, MINI-5w7g-3mxm-c368, MINI-66fh-jrq9-9gpr, MINI-6mqh-p9g4-59h3, MINI-79xv-353r-cmx6, MINI-7h88-4rvw-p8qc, MINI-96r5-rp8c-hr53, MINI-f724-6xwm-4hv8, MINI-fmqj-4w2r-3392, MINI-gp9c-r42q-8m3v, MINI-gqwv-363w-2f6h, MINI-jm48-8xhv-932g, MINI-jqc8-6fg2-g4vx, MINI-m22j-hw85-rfff, MINI-mfwj-rcx4-g6r9, MINI-mhj5-j4v6-56x8, MINI-pgpg-66wj-9wvm, MINI-pv8j-fv86-gq92, MINI-qwcx-v83v-fqqh, MINI-rwc4-jwhq-72w8, MINI-vvfh-5gwf-qr82, MINI-w3g4-vh5g-5gf3, MINI-wcxw-hq97-7v2h, MINI-wmx8-6rj8-v8p9, MINI-x5c7-8f4p-3xxm, PYSEC-2026-3545, ROOT-APP-PYPI-CVE-2026-69244, UBUNTU-CVE-2026-69244

## What is CVE-2026-69244?

CVE-2026-69244 is a high-severity memory corruption vulnerability in aio-libs aiohttp, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.3, an out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response. An attacker controlled server, or possibly an accidental response, could trigger a DoS in the client. The vulnerable path was error message construction in aiohttp/_http_parser.pyx, where an llhttp error-position pointer was used to build a snippet for malformed chunked responses and malformed request or response bytes at the buffer end. This issue is fixed in version 3.14.3.

Weakness: CWE-416 (Use After Free), CWE-400 (Uncontrolled Resource Consumption), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-69244?

3 open source packages ship an affected version, including aiohttp.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `aiohttp` | PyPI | All versions | 3.14.3 |
| `aiohttp` | PyPI | All versions | 3.14.3 |
| `aiohttp` | PyPI | All versions | 3.14.3 |

## How do I fix CVE-2026-69244?

Upgrade aiohttp to 3.14.3 or later.

## Is CVE-2026-69244 being exploited?

There is no known exploitation of CVE-2026-69244 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-69244 and fix it if it is affected.

What it is: CVE-2026-69244 is a high-severity memory corruption vulnerability in aio-libs aiohttp, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-69244 in the wild and no public exploit code.

Affected packages and fixed versions:
- aiohttp (PyPI): affected all versions; fixed in 3.14.3
- aiohttp (PyPI): affected all versions; fixed in 3.14.3
- aiohttp (PyPI): affected all versions; fixed in 3.14.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-69244/ (Markdown: https://insights.sbomify.com/CVE-2026-69244/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-69244
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-69244
- OSV: https://osv.dev/vulnerability/CVE-2026-69244

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-69244/
Summaries are generated and may contain mistakes; the official description above is the record.