Deserialization in Aiohttp
CVE-2026-34993
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.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:L/I:H/A:L.
EPSS exploit prediction
EPSS: 0.005 (41.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.005 · change: +0.003
Affected products
- Aiohttp
- Aio-Libs Aiohttp — versions < 3.14.0
Weakness classification (CWE)
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-jg22-mg44-37j8 (Patch, Mitigation, Vendor Advisory)
- https://github.com/aio-libs/aiohttp/commit/dcf40f30637e8752c76781cf6703b5a236749a00 (Patch)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-34993?
- CVE-2026-34993 is a medium-severity vulnerability in Aiohttp, classified under Deserialization of Untrusted Data. CVSS score: 6.4/10. Published 2026-06-02.
- How severe is CVE-2026-34993?
- Medium severity. CVSS v3 base score is 6.4 out of 10.