Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| aio-libs | aiohttp | < 3.14.2 | — |
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 | 3.14.3-1 | — |
| Debian 13 | python-aiohttp | No fix yet | — |
| Debian 12 | python-aiohttp | 3.8.4-1+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-aiohttp | No fix yet | — |
Show 6 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 22.04 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 | 3.6.0-150100.3.41.1 | SUSE-SU-2026:4113-1 |
| SLES 15 SP6 | python-aiohttp | 3.6.0-150100.3.41.1 | SUSE-SU-2026:4113-1 |
| SLES 15 SP5 | python-aiohttp | 3.6.0-150100.3.41.1 | SUSE-SU-2026:4113-1 |
| SLES 15 SP4 | python-aiohttp | 3.6.0-150100.3.41.1 | SUSE-SU-2026:4113-1, SUSE-SU-2026:4031-1 |
| SLES 3 | python-aiohttp | 3.9.3-150400.10.46.1 | SUSE-SU-2026:4031-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | python-aiohttp | 3.11.16-160000.7.1 | SUSE-SU-2026:23571-1 |
| SLES 16.0 | python-aiohttp | 3.11.16-160000.7.1 | SUSE-SU-2026:23571-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-aiohttp | 3.14.3-1.1 | openSUSE-SU-2026:11467-1 |
| openSUSE Leap 16.0 | python-aiohttp | 3.11.16-160000.7.1 | openSUSE-SU-2026:21687-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | python-aiohttp | No fix yet | — |
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 | 3.3.0-r4 | — |
| Wolfi rolling | dask-kubernetes | 2026.3.0-r11 | — |
| Wolfi rolling | kserve +2 | 0.20.0-r7 | — |
| Wolfi rolling | open-webui | 0.11.0-r6 | — |
| Wolfi rolling | py3-cassandra-medusa | 0.29.1-r1 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | aiohttp | < 3.14.2 | 3.14.2 | GHSA-mq44-7p77-q5h7 |
Advisories 6
- ELSA-2026-604898 Important: python-oci-sdk security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 21, 2026
- SUSE-SU-2026:23571-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:4113-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Sep 14, 2026
- SUSE-SU-2026:4031-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Sep 13, 2026
- openSUSE-SU-2026:21687-1 Security update for python-aiohttp SUSE / openSUSE Security Updates · Aug 31, 2026
- openSUSE-SU-2026:11467-1 python313-aiohttp-3.14.3-1.1 on GA media SUSE / openSUSE Security Updates · Aug 7, 2026