CVE-2025-69224: Aiohttp AIOHTTP's Unicode Processing Of Header Vulnerability
LOWCVE-2025-69224 is a LOW aiohttp's unicode processing of header vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Aiohttp libraries in the PyPI ecosystem. The issue involves aiohttp's unicode processing of header values could cause parsing discrepancies. Remediation is available by upgrading affected packages to version 3.13.3.
CVE-2025-69224 at a Glance
How to Fix CVE-2025-69224
To remediate this vulnerability, upgrade all affected Aiohttp dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
pip install aiohttp>=3.13.3
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
pip show aiohttp
How to Check if You Are Affected
To determine whether your Python environment is affected by CVE-2025-69224, inspect your installed packages using pip:
pip show aiohttp
Analyze the terminal output to locate any version of Aiohttp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.13.3), your application is affected.
Note: The pip show aiohttp command checks currently installed packages in your active Python environment.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where 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. In Aiohttp, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2025-69224 Affected Aiohttp Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
aiohttp
|
PyPI |
< 3.13.3
|
3.13.3
|
References
Frequently Asked Questions
What is CVE-2025-69224?
Which Aiohttp versions are affected?
What version fixes CVE-2025-69224?
Is aiohttp affected?
What CWE is associated with CVE-2025-69224?
How can I check PyPI dependencies for CVE-2025-69224?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-69f9-5gxw-wvc2",
"modified" : "2026-01-06T16:06:40Z",
"published" : "2026-01-05T22:58:57Z",
"aliases" : [ "CVE-2025-69224" ],
"summary" : "AIOHTTP's unicode processing of header values could cause parsing discrepancies",
"details" : "### Summary\nThe Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters.\n\n### Impact\nIf a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections.\n\n------\n\nPatch: https://github.com/aio-libs/aiohttp/commit/32677f2adfd907420c078dda6b79225c6f4ebce0",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "PyPI",
"name" : "aiohttp"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "3.13.3"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 3.13.2"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-69f9-5gxw-wvc2"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-69224"
}, {
"type" : "WEB",
"url" : "https://github.com/aio-libs/aiohttp/commit/32677f2adfd907420c078dda6b79225c6f4ebce0"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/aio-libs/aiohttp"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-444" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-01-05T22:58:57Z",
"nvd_published_at" : "2026-01-05T23:15:40Z"
}
}