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CVE-2026-34520

Published: Apr 1, 2026

Modified: Apr 4, 2026

PUBLISHED

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser (the default for most installs) accepted null bytes and control characters in response headers. This issue has been patched in version 3.13.4.

Vendor	Product	Versions
aio-libs	aiohttp	affected `< 3.13.4`

Weaknesses (CWE)

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hf-3vf5-4wqf

x_refsource_CONFIRM

https://github.com/aio-libs/aiohttp/commit/9370b9714a7a56003cacd31a9b4ae16eab109ba4

x_refsource_MISC

https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4

x_refsource_MISC

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