Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request server_hostname parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check. This vulnerability is fixed in 3.14.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| aio-libs | aiohttp | < 3.14.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | python-aiohttp | 3.14.1-1 | — |
| Debian 13 | python-aiohttp | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-aiohttp | No fix yet | — |
| Ubuntu 25.10 | python-aiohttp | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | python-aiohttp | No fix yet | — |
| Ubuntu Pro 24.04 LTS | python-aiohttp | No fix yet | — |
| Ubuntu Pro 20.04 LTS | python-aiohttp | No fix yet | — |
| Ubuntu Pro 18.04 LTS | python-aiohttp | No fix yet | — |
| Ubuntu Pro 16.04 LTS | python-aiohttp | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | python-aiohttp | 3.6.0-150100.3.38.1 | SUSE-SU-2026:3208-1 |
| SLES 15 SP6 | python-aiohttp | 3.6.0-150100.3.38.1 | SUSE-SU-2026:3208-1, SUSE-SU-2026:3207-1 |
| SLES 15 SP5 | python-aiohttp | 3.6.0-150100.3.38.1 | SUSE-SU-2026:3208-1, SUSE-SU-2026:3207-1 |
| SLES 15 SP4 | python-aiohttp | 3.6.0-150100.3.38.1 | SUSE-SU-2026:3208-1, SUSE-SU-2026:3207-1 |
| SLES 3 | python-aiohttp | 3.9.3-150400.10.43.1 | SUSE-SU-2026:3207-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | python-aiohttp | 3.11.16-160000.6.1 | SUSE-SU-2026:22819-1 |
| SLES for SAP 15 SP6 | python-aiohttp | 3.9.3-150400.10.43.1 | SUSE-SU-2026:3207-1 |
| SLES for SAP 15 SP5 | python-aiohttp | 3.9.3-150400.10.43.1 | SUSE-SU-2026:3207-1 |
| SLES for SAP 15 SP4 | python-aiohttp | 3.9.3-150400.10.43.1 | SUSE-SU-2026:3207-1 |
| SLES 16.0 | python-aiohttp | 3.11.16-160000.6.1 | SUSE-SU-2026:22819-1 |
| SLE HPC 15 SP5 | python-aiohttp | 3.9.3-150400.10.43.1 | SUSE-SU-2026:3207-1 |
| SLE HPC 15 SP4 | python-aiohttp | 3.9.3-150400.10.43.1 | SUSE-SU-2026:3207-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-aiohttp | 3.14.1-1.1 | openSUSE-SU-2026:11097-1 |
| openSUSE Leap 16.0 | python-aiohttp | 3.11.16-160000.6.1 | openSUSE-SU-2026:21372-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | python39-oci-sdk +1 | 2.187.0-1.0.5.el9 | ELSA-2026-604898 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | airflow-3 | 3.2.2-r7 | — |
| Wolfi rolling | open-webui | 0.9.6-r5 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | aiohttp | < 3.14.1 | 3.14.1 | GHSA-4m7w-qmgq-4wj5 |
Advisories 6
- ELSA-2026-604898 Important: python-oci-sdk security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 21, 2026
- SUSE-SU-2026:22819-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Jul 28, 2026
- SUSE-SU-2026:3207-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Jul 24, 2026
- SUSE-SU-2026:3208-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Jul 24, 2026
- openSUSE-SU-2026:21372-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Jul 22, 2026
- openSUSE-SU-2026:11097-1 python311-aiohttp-3.14.1-1.1 on GA media SUSE / openSUSE Security Updates · Jun 24, 2026