aio-libs aiohttp up to 3.13.2 Parser request smuggling

Summaryinfo

A vulnerability was found in aio-libs aiohttp up to 3.13.2. It has been declared as problematic. Affected by this issue is some unknown functionality of the component Parser. Executing a manipulation can lead to request smuggling. The identification of this vulnerability is CVE-2025-69225. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in aio-libs aiohttp up to 3.13.2. It has been declared as problematic. This vulnerability affects some unknown processing of the component Parser. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. 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. As an impact it is known to affect integrity. CVE summarizes:

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below contain parser logic which allows non-ASCII decimals to be present in the Range header. There is no known impact, but there is the possibility that there's a method to exploit a request smuggling vulnerability. This issue is fixed in version 3.13.3.

The advisory is shared for download at github.com. This vulnerability was named CVE-2025-69225 since 12/29/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 281865 (Linux Distros Unpatched Vulnerability : CVE-2025-69225), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.13.3 eliminates this vulnerability. Applying the patch c7b7a044f88c71cefda95ec75cdcfaa4792b3b96 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at CNNVD (CNNVD-202601-959) and Tenable (281865). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• aio-libs

Name

• aiohttp

Version

• 3.13.0
• 3.13.1
• 3.13.2

License

• open-source

Website

• Product: https://github.com/aio-libs/aiohttp/

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Once again VulDB remains the best source for vulnerability data.

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