Reliance on Cookies without Validation and Integrity Checking Affecting aiohttp package, versions [,3.14.4)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published20 Oct 2026
- disclosed20 Oct 2026
- creditDenys Pakizh
Introduced: 20 Oct 2026
NewCVE-2026-111749 (opens in a new tab)How to fix?
Upgrade aiohttp to version 3.14.4 or higher.
Overview
Affected versions of this package are vulnerable to Reliance on Cookies without Validation and Integrity Checking via _delete_cookies and update_cookies in aiohttp/cookiejar.py, where the host-only flag for a cookie is keyed only on (domain, name) instead of the full (domain, path, name) identity. When a host-only cookie expires or is deleted, _host_only_cookies.discard uses the wrong key and fails to remove the entry, causing the host-only state to persist incorrectly. A subsequent response can then set a domain cookie with the same name that is incorrectly treated as host-only, or a host-only cookie may be leaked to subdomains it should not reach.