AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
Priority LOW 31CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Partial Red Hat: 2 fixed, 15 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00524 44th percentileScored 2026-11-07
Fix Partial aiohttp (aio-libs): 3.14.2aiohttp (PyPI): 3.14.2Red Hat: 7 advisoriesRed Hat: 2 fixed, 15 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| aio-libs | aiohttp | before 3.14.2 | 3.14.2 | Patch available | CNA |
| — | aiohttp (PyPI) | before 3.14.2 | 3.14.2 | Patch available | GHSA-mq44-7p77-q5h7 |
- aiohttp Vendoraio-libs Affected before 3.14.2 Fixed in 3.14.2 Patch available CNA
- aiohttp (PyPI) Vendor— Affected before 3.14.2 Fixed in 3.14.2 Patch available GHSA-mq44-7p77-q5h7
Remediation
- Fix · CNA aiohttp (aio-libs) Fixed in 3.14.2
- Fix · GHSA-mq44-7p77-q5h7 aiohttp (PyPI) Fixed in 3.14.2 Advisory →
Red Hat 7 advisories
- RHSA-2026:73930 Released 2026-09-30 · Red Hat rating ImportantRed Hat AI Inference Server 3.2.2 (rocm)
- Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/vllm-rocm-rhel9
- RHSA-2026:73929 Released 2026-09-30 · Red Hat rating ImportantRed Hat AI Inference Server 3.2.2 (cuda)
- Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/vllm-cuda-rhel9
- RHSA-2026:73859 Released 2026-09-30 · Red Hat rating ImportantRed Hat AI Inference Server Model Optimization Tools 3.2.2 (CUDA)
- Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/model-opt-cuda-rhel9
Show 4 more Red Hat advisories
- RHSA-2026:70995 Released 2026-09-23 · Red Hat rating ImportantRed Hat AI Inference 3.4.5 (rocm)
- Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-rocm-rhel9
- RHSA-2026:70979 Released 2026-09-23 · Red Hat rating ImportantRed Hat AI Inference 3.4.5 (cuda)
- Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-cuda-rhel9
- RHSA-2026:70969 Released 2026-09-23 · Red Hat rating ImportantRed Hat AI Inference 3.4.5 (spyre)
- Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-spyre-rhel9
- RHSA-2026:70965 Released 2026-09-23 · Red Hat rating ImportantRed Hat AI Inference 3.4.5 (cpu)
- Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-cpu-rhel9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Exploit Intelligence | Affected | No fix yet: Fix deferred |
| Lightspeed Core | Affected | No fix yet: Fix deferred |
| Migration Toolkit for Applications 8 | Affected | No fix yet: Fix deferred |
| OpenShift Lightspeed | Affected | No fix yet: Fix deferred |
| Red Hat AI Inference Server | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform Ansible Core 2 | Affected | No fix yet: Fix deferred |
| Red Hat Discovery 2 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Red Hat Satellite 6 | Affected | No fix yet: Fix deferred |
| Red Hat Update Infrastructure 4 for Cloud Providers | Affected | No fix yet: Fix deferred |
| Red Hat Update Infrastructure 5 | Affected | No fix yet: Fix deferred |
| Red Hat AI Inference Server 3.2 | Fixed | RHSA-2026:73859, RHSA-2026:73929, RHSA-2026:73930 |
| Red Hat AI Inference Server 3.4 | Fixed | RHSA-2026:70965, RHSA-2026:70969, RHSA-2026:70979, RHSA-2026:70995 |
Not affected: 3 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat Hardened Images
Timeline
- 2026-10-02 Threatist record created from CVE-2026-59881
- 2026-10-03 Alias added: GHSA-mq44-7p77-q5h7
References
Other 5
More aio-libs vulnerabilities
- TI-2025-38826 aiomysql allows arbitrary access to client files through vulnerability of a malicious MySQL server CVSS 4.0HIGH 8.2
- TI-2024-15436 aiohttp.web.static(follow_symlinks=True) is vulnerable to directory traversal CVSS 3.1HIGH 7.5
- TI-2023-25769 Request smuggling in aiohttp CVSS 3.1HIGH 7.5
- TI-2023-18906 aiohttp vulnerable to HTTP request smuggling CVSS 3.1HIGH 7.5
- TI-2023-26746 aiohttp's ClientSession is vulnerable to CRLF injection via version CVSS 3.1HIGH 7.2
- TI-2026-66145 Multidict: Reference leak in CIMultiDict/MultiDict items-view union and subtraction CVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-59881 · CVE Program
- CVE-2026-59881 · NVD
- FIRST EPSS
- GHSA-mq44-7p77-q5h7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-59881 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences