GHSA-mfx4-hv73-q22v CVE-2026-69243 PYSEC-2026-3546
AIOHTTP: HTTP request smuggling via WebSocket upgrade
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.44%
- Chance of exploitation in the next 30 days. Higher than 38.53% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
- Fix
3.14.2- Upgrade aiohttp to this version or later
Description
Summary
The HTTP parsers were vulnerable to a request smuggling attack relating to WebSocket upgrades.
Impact
If using the server-side component, it may be possible for an attacker to execute a request smuggling vulnerability using an edge case in the WebSocket upgrade procedure. AIOHTT is unaware of any public exploit code.
Patch: https://github.com/aio-libs/aiohttp/commit/6ae358f0983c3f4d6f67692b2f8e65dc8e091c98
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| aiohttp | < 3.14.2 |
3.14.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
aiohttp PyPI → 3.14.2
- pip
pip install --upgrade "aiohttp>=3.14.2"- poetry
poetry add "aiohttp>=3.14.2"- uv
uv add "aiohttp>=3.14.2"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- High
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
How to prevent it
- Implementation: Use a web server that employs a strict HTTP parsing procedure, such as Apache [REF-433].
- Implementation: Use only SSL communication.
- Implementation: Terminate the client session after each request.
- System Configuration: Turn all pages to non-cacheable.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-pqxq-w44r-73xw AIOHTTP: Pure-Python parser request smuggling | Medium | Also affects aiohttp |
| GHSA-gx76-c99x-2c96 AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies | Low | Also affects aiohttp |
| GHSA-f9xw-jh8m-3mwq AIOHTTP: Absolute-form request targets can spoof Request.scheme | Medium | Also affects aiohttp |
| GHSA-9xw5-w5jj-pvcg AIOHTTP: File descriptor exhaustion in multipart requests | High | Also affects aiohttp |
| GHSA-6cjc-53gc-5rqm AIOHTTP: Connector pool exhaustion via Max-Age overflow | Medium | Also affects aiohttp |
| GHSA-5wr8-gcqf-gqf3 aiohttp server lacks an initial request/header timeout | High | Also affects aiohttp |
| GHSA-494j-54xm-rwp3 AIOHTTP: Secure attribute not enforced for shared cookie | Medium | Also affects aiohttp |
| GHSA-2g87-pp6c-29x5 aiohttp: Multiple instances of excessive or unbounded memory/CPU use | High | Also affects aiohttp |
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