Low severity · published Oct 19, 2026
CVE-2026-111749
AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies
2.3
CVSS
0.4%
EPSS
No
On KEV
Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Host-Only scope on an existing parent-domain cookie can be removed by a subdomain. A user who accesses an untrusted subdomain can consequently have host-only protections stripped from cookies, although impact is limited when applications do not reflect those cookies to a browser. This issue is fixed in version 3.14.4.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AI
aiohttp · aio-libs
< 3.14.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-111749
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-111749
github.com
https://github.com/aio-libs/aiohttp/commit/6a07c171ef9f3be583e2907dcd1931372efca8d6
github.com
https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4
github.com
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-gx76-c99x-2c96
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