CVE-2026-34993: AIOHTTP Vulnerable to Deserialization of Untrusted Data

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-02 · updated 2026-09-04
Weakness: CWE-502

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, using ``CookieJar.load()`` with untrusted input may allow arbitrary code execution. Most applications using this function will be doing so with the user's own data, so this is unlikely to affect many applications. Version 3.14.0 patches the issue. If an application does allow attacker controlled files to be loaded, a workaround on older releases would be to sanitize the files before loading.

Affected products

aio-libs aiohttp: before 3.14.0 — fixed in 3.14.0
Pypi Aiohttp: before 3.14.0; 0.1, 0.10.0, 0.10.1, 0.10.2, 0.11.0, 0.12.0 (+300) — fixed in 3.14.0

How to fix

Upgrade to a fixed version: aio-libs aiohttp 3.14.0; Pypi Aiohttp 3.14.0. Check the vendor advisory for mitigations.

References

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