GHSA-pqxq-w44r-73xw CVE-2026-111750
AIOHTTP: Pure-Python parser request smuggling
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.38%
- Chance of exploitation in the next 30 days. Higher than 32.19% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
- Fix
3.14.4- Upgrade aiohttp to this version or later
Description
Summary
The pure Python parser is vulnerable to an HTTP request smuggling attack.
Impact
If users are using the Python parser (AIOHTTP_NO_EXTENSIONS, or not a standard wheel installed), then an application may be vulnerable to a request smuggling attack.
Workaround
Switch to the default C parser.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| aiohttp | < 3.14.4 |
3.14.4 |
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 → 3.14.4
- pip
pip install --upgrade "aiohttp>=3.14.4"- poetry
poetry add "aiohttp>=3.14.4"- uv
uv add "aiohttp>=3.14.4"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- Low
- Availability (subsequent systems)
- Low
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-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 |
| GHSA-cq5v-8q36-5273 AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response) | High | Also affects aiohttp |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor