CVE-2026-34993: AIOHTTP Vulnerable to Deserialization of Untrusted Data
Summary
Using CookieJar.load() with untrusted input may allow arbitrary code execution.
Impact
Most applications using this function will be doing so with the user's own data, so this is unlikely to affect many applications.
Workaround
If an application does allow attacker controlled files to be loaded, a workaround on older releases would be to sanitise the files before loading.
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Patch: https://github.com/aio-libs/aiohttp/commit/dcf40f30637e8752c76781cf6703b5a236749a00
Other sources
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.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
pip/aiohttpto a version that resolves this vulnerability.Fixed in 3.14.0 - Upgrade
Upgrade
aiohttpto a version that resolves this vulnerability.Fixed in 3.14.0Patch dcf40f30637e8752c76781cf6703b5a236749a00 - Configuration
On releases prior to 3.14.0, if applications use CookieJar.load() with attacker-controlled (untrusted) input, sanitize the files before loading.
aiohttp.CookieJar load() input handling = Sanitize files before loading
Event History
Frequently Asked Questions
What is the severity of CVE-2026-34993?
The severity of CVE-2026-34993 is medium with a score of 6.4.
What vulnerability is identified by CVE-2026-34993?
CVE-2026-34993 is a deserialization vulnerability in AIOHTTP that can lead to arbitrary code execution when using untrusted input with CookieJar.load().
How do I fix CVE-2026-34993?
To fix CVE-2026-34993, update AIOHTTP to version 3.14.0 or later, which addresses this security risk.
What is the impact of CVE-2026-34993?
CVE-2026-34993 can potentially allow attackers to execute arbitrary code within applications using vulnerable versions of AIOHTTP.
Who is affected by CVE-2026-34993?
Users of AIOHTTP versions prior to 3.14.0 who use CookieJar.load() with untrusted data may be affected by CVE-2026-34993.