CVE-2026-69244 — aiohttp
Fix: aio-libs/aiohttp@49f65d5CVE-2026-69244 is a Out-of-bounds Read vulnerability in aiohttp. A fix is available for aiohttp — see the affected versions and patch details below.
AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-69244.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
aiohttpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | aiohttp | all versions | 3.14.3pip install --upgrade 'aiohttp==3.14.3' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aiohttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update aiohttp to 3.14.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-69244 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-69244 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-69244. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This is an Important severity flaw in aiohttp that could lead to a denial of service in client applications. A remote, malicious HTTP server could send a specially crafted response, causing an out-of-bounds read in the aiohttp C response parser and resulting in the client application terminating unexpectedly.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.5 for RHEL 8 | automation-controller-0:4.6.32-1.el8ap | RHSA-2026:59135 |
| Red Hat Ansible Automation Platform 2.6 for RHEL 9 | automation-controller-0:4.7.16-1.el9ap | RHSA-2026:59136 |
| Red Hat Satellite 6.16 for RHEL 8 | python-aiohttp-0:3.14.3-1.el8pc | RHSA-2026:63327 |
| Red Hat Satellite 6.17 for RHEL 9 | ansible-core-1:2.16.19-1.el9sat | RHSA-2026:63387 |
| Red Hat Satellite 6.18 for RHEL 9 | pulpcore-obsolete-packages-0:1.3.1-5.el9pc | RHSA-2026:63386 |
| Red Hat Satellite 6.19 for RHEL 9 | python3.12-aiohttp-0:3.14.3-1.el9pc | RHSA-2026:63385 |
| Red Hat Ansible Automation Platform 2.18 | ansible-automation-platform/ee-minimal-rhel8:1786971288 | RHSA-2026:55853 |
| Red Hat Ansible Automation Platform 2.18 | ansible-automation-platform/ee-minimal-rhel9:1786942232 | RHSA-2026:55852 |
Frequently Asked Questions
Is CVE-2026-69244 in your dependencies?
O3 Security finds CVE-2026-69244 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.