Improper Validation of Certificate with Host Mismatch Affecting aiohttp package, versions [,3.14.1)
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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- published16 Jun 2026
- disclosed15 Jun 2026
- creditDenys Pakizh
Introduced: 15 Jun 2026
NewCVE-2026-54275 (opens in a new tab)How to fix?
Upgrade aiohttp to version 3.14.1 or higher.
Overview
Affected versions of this package are vulnerable to Improper Validation of Certificate with Host Mismatch in the server_hostname parameter handling during HTTPS connection reuse. An attacker can bypass intended TLS SNI checks by reusing an existing connection with a different server_hostname, potentially allowing connections to unintended hosts.