CVE-2026-54275CWE-297

AIOHTTP: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections

Low · published June 22, 2026

CVSS v4.0
2.7
EPSS
0%
Percentile
39.7
In the wild
Unconfirmed
What it is

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request server_hostname parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check. This vulnerability is fixed in 3.14.1.

The record
Technical detail
CVSS v4.0
2.7 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
EPSS
0.00470 · 39.7th percentile
Weakness
CWE-297 · Improper Validation of Certificate with Host Mismatch
Published
2026-06-22T16:34Z
EPSS history
Timeline
  • 22 JUN 16:34Z
    AIOHTTP: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections
    cvelistv5